A113884 Pentanacci analog of A055502.

0, 2, 3, 7, 13, 29, 59, 113, 223, 439, 877, 1721, 3389, 6653, 13093, 25741, 50599, 99487, 195581, 384509, 755959

Offset

0,2

Comments

This is to the pentanacci sequence as A055502 is to the Fibonacci sequence and A113823 is to the tribonacci sequence (i.e., least prime greater than the sum of the previous 2 terms in A055502, least prime greater than the sum of the previous 3 terms in A113823, least prime greater than the sum of the previous 5 terms in this sequence).

Links

Table of n, a(n) for n=0..20.

Formula

a(-n) = a(0) = 0, a(1) = 2, for n>1: a(n) = smallest prime > a(n-1)+a(n-2)+a(n-3)+a(n-4)+a(n-5).

Example

a(6) = 59 because a(1)+a(2)+a(3)+a(4)+a(5) = 2+3+7+13+29 = 54, the smallest prime beyond 54 is 59.
a(10) = 877 because a(5)+a(6)+a(7)+a(8)+a(9) = 29 + 59 + 113 + 223 + 439 = 863 is prime, the next prime being 14 more, namely 877.

Crossrefs

Cf. A055502, A113823.

Sequence in context: A113843 A199582 A255516 * A070218 A048456 A333313

Adjacent sequences: A113881 A113882 A113883 * A113885 A113886 A113887

Keyword

easy,nonn

Author

Jonathan Vos Post, Jan 27 2006

Status

approved