A277821 Inverse permutation to A277820.

1, 3, 2, 10, 4, 5, 6, 36, 9, 8, 28, 14, 15, 21, 7, 136, 11, 27, 120, 19, 91, 105, 20, 44, 45, 55, 13, 78, 35, 12, 66, 528, 77, 17, 496, 90, 435, 465, 43, 53, 325, 351, 54, 406, 18, 65, 378, 152, 153, 171, 16, 210, 135, 34, 190, 300, 26, 119, 276, 25, 231, 253, 104, 2080, 118, 275, 2016, 32, 1891, 1953, 252, 324, 1653, 1711, 33

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..16383

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 = A277818(n), and r = A268671(n).

Prog

(Scheme)
(define (A277821 n) (let ((row (A268671 n)) (col (A277818 n))) (* (/ 1 2) (- (expt (+ row col) 2) row col col col -2))))

Crossrefs

Inverse: A277820.

Cf. A268671, A277818.

Sequence in context: A220466 A090780 A184174 * A371220 A318280 A057977

Adjacent sequences: A277818 A277819 A277820 * A277822 A277823 A277824

Keyword

nonn

Author

Antti Karttunen, Nov 03 2016

Status

approved