A277881 Inverse permutation to A277880.

1, 3, 2, 6, 5, 4, 10, 15, 9, 8, 21, 7, 28, 36, 14, 45, 20, 13, 55, 12, 66, 78, 27, 11, 91, 105, 35, 120, 44, 19, 136, 153, 54, 26, 171, 18, 190, 210, 65, 17, 231, 253, 77, 276, 90, 34, 300, 16, 325, 351, 104, 378, 119, 43, 406, 435, 135, 53, 465, 25, 496, 528, 152, 561, 170, 64, 595, 33, 630, 666, 189, 24, 703, 741, 209, 780, 230, 76, 820, 23

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..16384

Index entries for sequences that are permutations of the natural numbers

Formula

a(n) = (1/2) * ((c+r)^2 - r - 3*c + 2), where c = A277822(n), and r = A277813(n).

Prog

(Scheme) (define (A277881 n) (let ((row (A277813 n)) (col (A277822 n))) (* (/ 1 2) (- (expt (+ row col) 2) row col col col -2))))

Crossrefs

Inverse: A277880.

Cf. A277813, A277822.

Cf. A028401 (terms at powers of 2).

Sequence in context: A194910 A194909 A038722 * A145522 A283939 A293056

Adjacent sequences: A277878 A277879 A277880 * A277882 A277883 A277884

Keyword

nonn

Author

Antti Karttunen, Nov 03 2016

Status

approved