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

Author

David Applegate, Oct 26 2007

Keywords

• nonn

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

Crossrefs

Cf. A134204.

Programs

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 *)