A252460 Inverse permutation to A083221 considered as a permutation of natural numbers (with assumption that a(1) = 1).

1, 2, 4, 3, 7, 5, 11, 8, 6, 12, 16, 17, 22, 23, 9, 30, 29, 38, 37, 47, 13, 57, 46, 68, 10, 80, 18, 93, 56, 107, 67, 122, 24, 138, 14, 155, 79, 173, 31, 192, 92, 212, 106, 233, 39, 255, 121, 278, 15, 302, 48, 327, 137, 353, 19, 380, 58, 408, 154, 437, 172, 467, 69, 498, 25, 530, 191, 563, 81, 597, 211, 632, 232, 668, 94, 705, 20

Offset

1,2

Links

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

Index entries for sequences that are permutations of the natural numbers

Formula

a(1) = 1; for n>1: a(n) = 2 + ((((x+y)^2) - x - 3*y)/2), where x = A055396(n) and y = A078898(n).

a(1) = 1; for n>1: a(n) = 1 + A249742(n-1).

Prog

(Scheme. Two variants)
(define (A252460 n) (if (<= n 1) n (let ((x (A055396 n)) (y (A078898 n))) (+ 1 (* (/ 1 2) (- (expt (+ x y) 2) x y y y -2))))))
(define (A252460 n) (if (<= n 1) n (+ 1 (A249742 (- n 1)))))

Crossrefs

Essentially after a(1) one more than A249742.

Inverse permutation: A083221.

Cf. A055396, A078898.

Sequence in context: A364887 A365231 A255128 * A252752 A056536 A258237

Adjacent sequences: A252457 A252458 A252459 * A252461 A252462 A252463

Keyword

nonn,look

Author

Antti Karttunen, Dec 19 2014

Status

approved