A278512 Inverse permutation to A278511.

1, 2, 4, 3, 6, 5, 7, 8, 10, 12, 9, 17, 11, 23, 15, 30, 13, 38, 16, 47, 14, 57, 18, 68, 21, 80, 22, 93, 24, 107, 28, 122, 19, 138, 31, 155, 20, 173, 29, 192, 39, 212, 36, 233, 25, 255, 48, 278, 37, 302, 27, 327, 58, 353, 26, 380, 32, 408, 69, 437, 45, 467, 46, 498, 81, 530, 55, 563, 40, 597, 94, 632, 35, 668, 33

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(n) = (1/2) * ((c+r)^2 - r - 3*c + 2), where c = A278537(n) and r = A278538(n).

Prog

(define (A278512 n) (if (= 1 n) n (let ((row (A278538 n)) (col (A278537 n))) (+ 1 (* (/ 1 2) (- (expt (+ row col) 2) row col col col -2))))))

Crossrefs

Inverse: A278511.

Cf. A278537, A278538.

Cf. also A278504, A278506.

Sequence in context: A161920 A366943 A366945 * A278511 A255552 A255551

Adjacent sequences: A278509 A278510 A278511 * A278513 A278514 A278515

Keyword

nonn

Author

Antti Karttunen, Nov 23 2016

Status

approved