A328703 Numbers k dividing nonzero terms in A002065.

1, 3, 13, 39, 61, 151, 169, 183, 211, 223, 453, 507, 633, 669, 739, 793, 1009, 1531, 1963, 2197, 2217, 2379, 2743, 2899, 3027, 3721, 4363, 4513, 4593, 5503, 5889, 6277, 6397, 6591, 7753, 7873, 8229, 8697, 9211, 9463, 9607, 10309, 11163, 11353, 11587, 11677, 12007, 12241, 12871

Offset

1,2

Comments

k is a term if and only if A328702(k) = 0, in which case all the indices m such that k divides A002065(m) are m = t*A328701(k), t = 0, 1, 2, 3, ...

Links

Table of n, a(n) for n=1..49.

Example

61 divides A002065(7) = 61, so 61 is in this sequence. In addition, 61 divides A002065(m) if and only if 4 divides m.
31 is not a term: {A002065(n) mod 31} = {0, 1, 3, 13, 28, 7, 26, 21, 29, 3, 13, 28, 7, 26, 21, 29, ...}, so 31 does not divides A002065(m) for any m > 0.

Prog

(PARI) v(n) = my(v=[0], k, flag=1); for(i=2, n+1, k=(v[#v]^2+v[#v]+1)%n; v=concat(v, k); for(j=1, i-1, if(v[j]==k, flag=0)); if(flag==0, break())); v
a(n) = !(v(n)[#v(n)])

Crossrefs

Cf. A002065, A328701, A328702.

The primes in this sequence are given by A328704.

Sequence in context: A054975 A072790 A323009 * A166911 A103657 A320661

Adjacent sequences: A328700 A328701 A328702 * A328704 A328705 A328706

Keyword

nonn

Author

Jianing Song, Oct 26 2019

Status

approved