A248921 Primes in the pentanacci numbers sequence A000322.

5, 17, 977, 28697, 56417, 1428864769, 2809074173, 21344178433, 626815657409, 18407729752001, 2317881588988297338942875602391948125494800020122167809, 136507010958920295813169620935932629930648432530102206331972221346174230852977164801

Offset: 1

Author

Robert Price, Oct 16 2014

Keywords

• nonn

Comments

a(13) is too large to display here. It has 132 digits and is the 450th term in A000322.

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..19

Crossrefs

Cf. A001590, A001631, A100683, A231574, A231575, A232543, A214899, A020992, A233554, A214727, A234696, A141523, A235862, A214825, A235873, A001630, A241660, A247027, A000288, A247561, A000322, A248920.

Programs

Mathematica

a={1,1,1,1,1}; For[n=5, n<=1000, n++, sum=Plus@@a; If[PrimeQ[sum], Print[sum]]; a=RotateLeft[a]; a[[5]]=sum]
Select[With[{c={1,1,1,1,1}},LinearRecurrence[c,c,300]],PrimeQ] (* Harvey P. Dale, Nov 30 2019 *)