A219674 a(n) = smallest prime not included earlier such that a(n-4) + a(n-3) + a(n-2) + a(n-1) + a(n) is a prime, with a(1)=1, a(2)=3, a(3)=5, and a(4)=7.

1, 3, 5, 7, 13, 19, 17, 11, 23, 31, 67, 41, 29, 43, 47, 37, 71, 53, 61, 59, 73, 101, 79, 89, 97, 83, 109, 113, 107, 151, 127, 103, 131, 149, 137, 139, 163, 173, 157, 179, 167, 181, 193, 191, 197, 229, 199, 223, 239, 227, 241, 233, 211, 251, 257, 271, 269, 313, 263

Offset

1,2

Links

Table of n, a(n) for n=1..59.

Mathematica

f[s_List] := Block[{pn = s[[-4]] + s[[-3]] + s[[-2]] + s[[-1]], p = 2}, While[ MemberQ[s, p] || ! PrimeQ[p + pn], p = NextPrime@ p]; Append[s, p]]; Nest[f, {1, 3, 5, 7}, 55]

Crossrefs

Cf. A073653.

Sequence in context: A227531 A079481 A291867 * A075571 A077133 A164642

Adjacent sequences: A219671 A219672 A219673 * A219675 A219676 A219677

Keyword

easy,nonn

Author

Robert G. Wilson v, Nov 28 2012

Status

approved