A257506 Inverse permutation to A257505.

1, 3, 6, 2, 10, 15, 21, 28, 36, 45, 55, 5, 66, 78, 91, 9, 105, 4, 120, 136, 153, 14, 171, 190, 210, 231, 253, 276, 300, 325, 351, 378, 406, 435, 465, 496, 528, 561, 595, 630, 666, 703, 741, 780, 820, 861, 903, 20, 946, 990, 1035, 27, 1081, 1128, 1176, 1225, 1275, 1326, 1378, 35, 1431, 1485, 1540, 44, 1596, 54, 1653, 1711, 1770, 65, 1830, 8

Offset

1,2

Links

Antti Karttunen, Table of n, a(n) for n = 1..5050

Index entries for sequences related to factorial base representation

Index entries for sequences that are permutations of the natural numbers

Formula

a(n) = (1/2) * ((c+r)^2 - r - 3*c + 2), where r = A257681(n), and c = A257679(n).

Prog

(Scheme) (define (A257506 n) (let ((row (A257681 n)) (col (A257679 n))) (* (/ 1 2) (- (expt (+ row col) 2) row col col col -2))))

Crossrefs

Inverse: A257505.

Cf. A257679, A257681.

Sequence in context: A210187 A364365 A210189 * A210035 A210199 A268717

Adjacent sequences: A257503 A257504 A257505 * A257507 A257508 A257509

Keyword

nonn

Author

Antti Karttunen, May 06 2015

Status

approved