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

2,6

Comments

A112050 interleaved with A000012.

Links

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

Formula

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

Prog

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

Crossrefs

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

Sequence in context: A373387 A309913 A317905 * A111620 A111628 A161974

Adjacent sequences: A227192 A227193 A227194 * A227196 A227197 A227198

Keyword

nonn

Author

Antti Karttunen, Jul 06 2013

Extensions

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

Status

approved