A166048 a(n) = (A166049(n)-1)/4.

0, 1, 2, 3, 5, 6, 9, 12, 20, 21, 23, 30, 41, 42, 56, 72, 90, 110, 132, 156, 182, 210, 240, 272, 306, 342, 380, 420, 462, 506, 552, 600, 650, 702, 756, 812, 870, 930, 992, 1056, 1122, 1190, 1260, 1332, 1406, 1482, 1560, 1640, 1722, 1806, 1892, 1980, 2070

Offset

1,3

Comments

Indexing sequence for A166049.

Links

Table of n, a(n) for n=1..53.

Prog

(MIT Scheme with macro MATCHING-POS by AK):
(define A166048 (MATCHING-POS 1 0 (lambda (n) (let ((w (A016813 n)) (hp (A005843 n))) (let loop ((i 1) (s 1)) (cond ((< s 0) #f) ((>= i hp) #t) (else (loop (1+ i) (+ s (jacobi-symbol (1+ i) w))))))))))

Crossrefs

Sequence in context: A241742 A212584 A330228 * A240306 A094873 A240726

Adjacent sequences: A166045 A166046 A166047 * A166049 A166050 A166051

Keyword

nonn

Author

Antti Karttunen, Oct 08 2009

Status

approved