A286456 Compound filter: a(n) = P(A056239(n), A243503(n)), with a(1) = 0, where P(n,k) is sequence A000027 used as a pairing function.

0, 1, 5, 5, 13, 18, 25, 13, 19, 40, 41, 40, 61, 71, 41, 25, 85, 41, 113, 83, 72, 111, 145, 71, 42, 160, 42, 142, 181, 84, 221, 41, 112, 218, 73, 72, 265, 285, 161, 142, 313, 143, 365, 217, 85, 361, 421, 111, 74, 85, 219, 308, 481, 73, 113, 238, 286, 446, 545, 143, 613, 540, 144, 61, 162, 218, 685, 415, 362, 144, 761, 112, 841, 643, 86, 538, 114, 309, 925, 217

Offset

1,3

Links

Antti Karttunen, Table of n, a(n) for n = 1..8192 (computed by using the b-files of A056239 and A243503)

Eric Weisstein's World of Mathematics, Pairing Function

Formula

a(1) = 0 and for n > 1, a(n) = (1/2)*(2 + ((A056239(n)+A243503(n))^2) - A056239(n) - 3*A243503(n)).

Prog

(Scheme) (define (A286456 n) (if (= 1 n) 0 (* (/ 1 2) (+ (expt (+ (A056239 n) (A243503 n)) 2) (- (A056239 n)) (- (* 3 (A243503 n))) 2))))

Crossrefs

Cf. A000027, A056239, A243503, A278520, A286454, A286455.

Sequence in context: A146370 A164927 A094904 * A352209 A171663 A126439

Adjacent sequences: A286453 A286454 A286455 * A286457 A286458 A286459

Keyword

nonn

Author

Antti Karttunen, May 14 2017

Status

approved