A302333 Wagstaff primes related to The New Mersenne Conjecture that are the indices of perfect numbers in a list of centered 9-gonal numbers.

3, 11, 43, 2731, 43691, 174763, 715827883, 768614336404564651, 56713727820156410577229101238628035243

Offset

1,1

Comments

Let p be a Wagstaff prime related to The New Mersenne Conjecture. Then (3p-2)(3p-1)/2 gives the perfect number whose index it is.

Links

Table of n, a(n) for n=1..9.

Caldwell and Honaker, 56713...35243 (38-digits), Prime Curios!

Eric Weisstein's World of Mathematics, New Mersenne Prime Conjecture

Example

For p = 3, (3*3-2)*(3*3-1)/2 = 28 and for p = 11, (3*11-2)(3*11-1)/2 = 496.

Crossrefs

Cf. A000979, A107360.

Sequence in context: A123628 A153476 A107290 * A345670 A370998 A239392

Adjacent sequences: A302330 A302331 A302332 * A302334 A302335 A302336

Keyword

nonn,more

Author

Steve Homewood, Apr 05 2018

Status

approved