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A256997
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Square array A(row,col) read by antidiagonals: A(1,col) = A055938(col), and for row > 1, A(row,col) = A005187(A(row-1,col)).
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13
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2, 5, 3, 6, 8, 4, 9, 10, 15, 7, 12, 16, 18, 26, 11, 13, 22, 31, 34, 49, 19, 14, 23, 41, 57, 66, 95, 35, 17, 25, 42, 79, 110, 130, 184, 67, 20, 32, 47, 81, 153, 215, 258, 364, 131, 21, 38, 63, 89, 159, 302, 424, 514, 723, 259, 24, 39, 73, 120, 174, 312, 599, 844, 1026, 1440, 515, 27, 46, 74, 143, 236, 343, 620, 1192, 1683, 2050, 2876, 1027
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OFFSET
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2,1
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COMMENTS
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The array is read by antidiagonals: A(1,1), A(1,2), A(2,1), A(1,3), A(2,2), A(3,1), etc.
This is transpose of array A256995.
If we assume that a(1) = 1 (but which is not explicitly included here because outside of the array proper), then A256998 gives the inverse permutation.
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LINKS
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FORMULA
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A(1,col) = A055938(col), and for row > 1, A(row,col) = A005187(A(row-1,col)).
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EXAMPLE
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The top left corner of the array:
2, 5, 6, 9, 12, 13, 14, 17, 20, 21, 24, 27
3, 8, 10, 16, 22, 23, 25, 32, 38, 39, 46, 50
4, 15, 18, 31, 41, 42, 47, 63, 73, 74, 88, 97
7, 26, 34, 57, 79, 81, 89, 120, 143, 145, 173, 191
11, 49, 66, 110, 153, 159, 174, 236, 281, 287, 341, 375
19, 95, 130, 215, 302, 312, 343, 467, 558, 568, 677, 743
35, 184, 258, 424, 599, 620, 680, 928, 1111, 1132, 1349, 1479
67, 364, 514, 844, 1192, 1235, 1356, 1852, 2216, 2259, 2693, 2951
131, 723, 1026, 1683, 2380, 2464, 2707, 3697, 4428, 4512, 5381, 5895
259, 1440, 2050, 3360, 4755, 4924, 5408, 7387, 8851, 9020, 10757, 11783
...
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PROG
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(Scheme)
(define (A256997bi row col) (if (= 1 row) (A055938 col) (A005187 (A256997bi (- row 1) col))))
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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