cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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A328703 Numbers k dividing nonzero terms in A002065.

Original entry on oeis.org

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

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Author

Jianing Song, Oct 26 2019

Keywords

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, ...

Examples

			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.
		

Crossrefs

The primes in this sequence are given by A328704.

Programs

  • 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)])
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