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A267104
Inverse permutation to A265903.
2
1, 3, 2, 6, 4, 7, 5, 10, 11, 16, 22, 8, 29, 12, 9, 15, 37, 46, 56, 67, 17, 79, 92, 23, 106, 30, 13, 121, 38, 18, 14, 21, 137, 154, 172, 191, 211, 47, 232, 254, 277, 57, 301, 326, 68, 352, 80, 24, 379, 407, 93, 436, 107, 31, 466, 122, 39, 19, 497, 138, 48, 25, 20, 28, 529, 562, 596, 631, 667, 704, 155, 742, 781, 821
OFFSET
1,2
FORMULA
a(n) = (1/2) * ((c+r)^2 - r - 3*c + 2), where c = A162598(n), and r = A265332(n).
PROG
(Scheme) (define (A267104 n) (let ((col (A162598 n)) (row (A265332 n))) (* (/ 1 2) (- (expt (+ row col) 2) row col col col -2))))
CROSSREFS
Inverse: A265903.
Sequence in context: A191444 A258241 A256739 * A093050 A289194 A321508
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 10 2016
STATUS
approved