

A186709


Number of quadratic residues (mod p) in the interval [2k+2,4k+2], for primes p=4k+3.


1



0, 1, 1, 3, 4, 6, 9, 9, 10, 15, 14, 17, 16, 23, 22, 29, 25, 30, 34, 39, 36, 37, 41, 45, 48, 52, 49, 52, 52, 59, 62, 66, 72, 68, 78, 79, 80, 87, 90, 87
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,4


LINKS

Table of n, a(n) for n=1..40.


FORMULA

a(n) = A104635(n)  A186708(n) = A186708(n)  A178154(n) = (A104635(n)  A178154(n))/2 = (A002145(n)  2*A178154(n) 1)/4.


PROG

(PARI) forprime( p=1, 399, p%4==3next; u=3; c=[1, 0]; for(i=2, p2, bittest(u, i^2%p) & next; u+=1<<(i^2%p); c[i^2%p*2\p+1]++); print1(c[2]", "))


CROSSREFS

Cf. A002145, A186708, A178154.
Sequence in context: A186700 A028987 A284615 * A143037 A225059 A190899
Adjacent sequences: A186706 A186707 A186708 * A186710 A186711 A186712


KEYWORD

nonn


AUTHOR

M. F. Hasler, Feb 25 2011


STATUS

approved



