A091385 Distance (A091382) of primes from the largest quadratic "mixed" residues modulo the primes (A091380), where the latter is non-monotonic.

2, 7, 11, 7, 11, 11, 7, 17, 7, 7, 7, 13, 11, 13, 7, 11, 7, 11, 13, 7, 11, 13, 11, 7, 11, 11, 13, 7, 7, 11, 13, 19, 11, 17, 11, 7, 7, 7, 13, 13, 17, 11, 11, 17, 11, 13, 19, 11, 13, 11, 7, 7, 11, 19, 11, 11, 7, 13, 11, 11, 13, 13, 7, 13, 17, 13, 11, 17, 11, 19, 11, 11, 11, 13, 23, 7, 17, 7

Offset

1,1

Comments

For n > 1, the values are some odd primes, but never < 7. The maximum value increases very slowly, it only reaches 43 for the first 10^5 primes.

Links

Table of n, a(n) for n=1..78.

Ferenc Adorjan, The sequence of largest quadratic residues modulo the primes

Prog

(PARI) {/* The distance of LQxR from the primes where the sequence of the largest "mixed" QR modulo the primes is non-monotonic */ lqxr_nm_pd(to)=local(v=[], k, r, q, p, e=1, n=0, i=1); while(n<to, i+=1; p=prime(i); k=p-1; r=p%4-2; while(kronecker(k, p)<>r, k-=1); if(k-e<=0, v=concat(v, p-k); n+=1); e=k); print(i); print(v) }

Crossrefs

Cf. A091380, A091381, A091382, A091383, A091384, A088195, A088201.

Sequence in context: A100020 A241807 A020638 * A053247 A226089 A208846

Adjacent sequences: A091382 A091383 A091384 * A091386 A091387 A091388

Keyword

easy,nonn

Author

Ferenc Adorjan (fadorjan(AT)freemail.hu)

Status

approved