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A277821 Inverse permutation to A277820. 3
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 (list; graph; refs; listen; history; text; internal format)
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 * A318280 A057977 A063549

Adjacent sequences:  A277818 A277819 A277820 * A277822 A277823 A277824

KEYWORD

nonn

AUTHOR

Antti Karttunen, Nov 03 2016

STATUS

approved

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Last modified May 24 18:34 EDT 2019. Contains 323534 sequences. (Running on oeis4.)