A260721 Half the difference between n-th odd Ludic and n-th Lucky number: a(1) = 0; a(n) = (A003309(n+1) - A000959(n))/2.

0, 0, -1, -1, -1, -1, -2, -1, -3, -2, 0, -1, -3, -2, -5, -3, -1, -1, 1, 2, 1, -1, -1, 1, 2, 2, -3, -1, -1, 4, 4, 3, 1, 5, 3, 4, -4, 0, 7, 5, 8, 6, 4, 5, 2, 2, 5, 8, 3, 8, 8, 7, 9, 11, 12, 16, 14, 15, 11, 16, 16, 15, 19, 17, 16, 18, 20, 15, 14, 14, 16, 12, 11, 12, 18, 19, 21, 15, 15, 11, 13, 13, 15, 19, 20, 15, 18, 23, 24, 23, 28, 27, 27, 27, 20, 23

Offset: 1

Author

Antti Karttunen, Aug 06 2015

Keywords

• sign

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000
• Index entries for sequences generated by sieves

Crossrefs

Cf. A000959, A003309, A260722, A256488.

Programs

Scheme

(define (A260721 n) (if (= 1 n) 0 (/ (- (A003309 (+ 1 n)) (A000959 n)) 2)))

Formula

a(1) = 0; a(n) = (A003309(n+1) - A000959(n))/2.

a(n) = A260722(n)/2.