A286595 Compound filter (2-adic valuation & deficiency/abundance): a(n) = P(A001511(n), A286449(n)), where P(n,k) is sequence A000027 used as a pairing function.

1, 3, 2, 6, 4, 12, 11, 10, 16, 5, 22, 48, 37, 8, 11, 15, 46, 68, 67, 108, 22, 107, 106, 175, 137, 30, 154, 18, 172, 138, 191, 21, 67, 173, 106, 256, 232, 57, 106, 329, 277, 138, 301, 13, 37, 353, 352, 501, 407, 467, 191, 24, 466, 138, 497, 634, 562, 632, 631, 744, 704, 192, 106, 28, 352, 138, 742, 39, 301, 38, 781, 950, 862, 597, 596, 58, 631, 138, 904, 1133, 407

Offset: 1

Author

Antti Karttunen, May 21 2017

Keywords

• nonn

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000
• Eric Weisstein's World of Mathematics, Pairing Function

Crossrefs

Cf. A000027, A001511, A033879, A033880, A286449, A286260, A286451, A286460, A286592, A286593.

Programs

Scheme

(define (A286595 n) (* (/ 1 2) (+ (expt (+ (A001511 n) (A286449 n)) 2) (- (A001511 n)) (- (* 3 (A286449 n))) 2)))

Formula

a(n) = (1/2)*(2 + ((A001511(n)+A286449(n))^2) - A001511(n) - 3*A286449(n)).