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A328493

a(n) = (p_n + 1)*q_n - 1; where (p_n, q_n) is the n-th twin prime pair.

19, 41, 155, 341, 929, 1805, 3659, 5255, 10505, 11771, 19181, 22649, 32579, 37055, 39401, 52211, 57839, 73169, 79805, 97655, 121451, 176819, 187055, 213905, 273005, 325469, 360599, 382541, 412805, 436259, 656909, 676505, 686411, 737021, 778805, 1041419, 1066055, 1103549, 1128905

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..39.

FORMULA

a(n) = A126251(n) - 1. - Michel Marcus, Oct 17 2019

EXAMPLE

For n = 2, the second twin prime pair is (5, 7). So (5 + 1) * 7 - 1 = 41 is the second term.

MATHEMATICA

(#[[1]]+1)#[[2]]-1&/@Select[Partition[Prime[Range[300]], 2, 1], #[[2]]- #[[1]] == 2&] (* Harvey P. Dale, Aug 30 2021 *)

PROG