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

Offset: 1

Author

Dimitris Valianatos, Oct 16 2019

Keywords

• nonn

Examples

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

Crossrefs

Cf. A001359, A006512, A126251.

Programs

Mathematica

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

PARI

my(p = 3); forprime(n=5, 2000, if(n - p == 2, print1((p + 1)*n - 1, ", ")); p=n)

Formula

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