A131261 a(0)=3; for n>0, a(n) = smallest odd prime not occurring earlier in the sequence such that a(n-1)+a(n) is a multiple of n.

3, 5, 7, 11, 13, 17, 19, 23, 41, 31, 29, 37, 47, 83, 43, 107, 53, 151, 101, 89, 71, 97, 79, 59, 61, 139, 173, 313, 163, 127, 113, 73, 311, 283, 193, 157, 131, 239, 103, 443, 197, 541, 257, 431, 229, 401, 887, 241, 191, 397, 353, 463, 109, 421, 227, 433, 631, 167

Offset

0,1

Comments

Is this sequence infinite and, if so, is it a permutation of the odd primes?

An analog of A134204, but using only the odd primes.

Links

Olivier Gérard, Table of n, a(n) for n = 0..1000

Mathematica

a = {3}; For[n = 1, n < 60, n++, i = 2; While[Length[Intersection[{Prime[i]}, a]] == 1 || Not[Mod[a[[ -1 ]] + Prime[i], n] == 0], i++ ]; AppendTo[a, Prime[i]]]; a (* Stefan Steinerberger, Oct 30 2007 *)

Crossrefs

Cf. A134204.

Sequence in context: A000978 A128925 A204142 * A100276 A225669 A065389

Adjacent sequences: A131258 A131259 A131260 * A131262 A131263 A131264

Keyword

nonn

Author

David Applegate, Oct 26 2007

Status

approved