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A368403
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Starts of runs of 3 consecutive integers in A268375.
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3
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1, 2, 3, 7, 11, 16, 17, 18, 27, 43, 47, 48, 79, 97, 147, 162, 171, 191, 241, 242, 243, 331, 367, 387, 431, 507, 547, 603, 907, 1051, 1249, 1250, 1619, 1871, 2267, 2347, 2523, 2799, 3411, 3643, 3987, 4049, 4050, 4111, 4175, 4203, 4491, 4923, 5119, 5391, 5407, 6091
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OFFSET
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1,2
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COMMENTS
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LINKS
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MATHEMATICA
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f[e_] := Position[Reverse[IntegerDigits[e, 2]], 1] // Flatten; q[n_] := UnsameQ @@ Flatten[f /@ FactorInteger[n][[;; , 2]]]; q[0] = False; seq[kmax_] := Module[{m = 3, s = {}, v}, v = q /@ Range[0, m - 1]; Do[v = Join[Rest[v], {q[k]}]; If[And @@ v, AppendTo[s, k - m + 1]], {k, m, kmax}]; s]; seq[6000]
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PROG
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(PARI) isA268375(n) = {my(e = factor(n)[, 2], b = 0); for(i=1, #e, b = bitor(b, e[i])); n == 1 || b == vecsum(e); }
lista(kmax) = {my(tri = vector(3, i, isA268375(i)), k = 4); while(k < kmax, if(vecsum(tri) == 3, print1(k-3, ", ")); tri = concat(vecextract(tri, "^1"), isA268375(k)); k++); }
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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