A286458 Compound filter: a(n) = P(A286448(n), A286449(n)), where P(n,k) is sequence A000027 used as a pairing function.

1, 1, 2, 3, 13, 25, 24, 15, 61, 5, 85, 113, 112, 64, 87, 55, 201, 243, 242, 313, 204, 393, 451, 513, 137, 22, 613, 250, 723, 651, 842, 276, 67, 844, 196, 1015, 1107, 657, 196, 1253, 1355, 1020, 1407, 559, 812, 795, 1744, 1864, 833, 2051, 1062, 101, 2181, 1363, 2384, 2524, 597, 2741, 2891, 3045, 3203, 1935, 1756, 1081, 1249, 1938, 3703, 1534, 441

Offset

1,3

Comments

For all i, j: a(i) = a(j) => A286385(i) = A286385(j).

Links

Antti Karttunen, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Pairing Function

Formula

a(n) = (1/2)*(2 + ((A286448(n)+A286449(n))^2) - A286448(n) - 3*A286449(n)).

a(n) = A286459(A048673(n)).

Prog

(Scheme) (define (A286458 n) (* (/ 1 2) (+ (expt (+ (A286448 n) (A286449 n)) 2) (- (A286448 n)) (- (* 3 (A286449 n))) 2)))

Crossrefs

Cf. A000027, A033879, A048673, A252748, A286385, A286448, A286449, A286459.

Sequence in context: A215134 A177746 A024779 * A087906 A029737 A191063

Adjacent sequences: A286455 A286456 A286457 * A286459 A286460 A286461

Keyword

nonn

Author

Antti Karttunen, May 14 2017

Status

approved