A227195 a(n) = one less than the first i >= 1 for which the Kronecker symbol K(i,n) is either 0 or -1. Or the maximal value u such that all K(1,n), K(2,n), ... up to K(u,n) have +1 as their values.

1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 4, 1, 4, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 4, 1, 6, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 6, 1, 4, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 4, 1, 4, 1, 1, 1, 1, 1, 2, 1, 2

Offset: 2

Author

Antti Karttunen, Jul 06 2013

Keywords

• nonn

Comments

A112050 interleaved with A000012.

Links

• Antti Karttunen, Table of n, a(n) for n = 2..10000

Crossrefs

Bisections: A112050 (for odd terms from 3 onward), A000012 (for all even terms).

Programs

PARI

A227195(n) = for(k=2, n, if(kronecker(k, n)<1, return(k-1))); \\ Antti Karttunen, Nov 08 2018

Formula

a(n) = A227196(n)-1 for all n >= 2.

Extensions

Data section extended up to a(105) by Antti Karttunen, Nov 08 2018