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A286458
Compound filter: a(n) = P(A286448(n), A286449(n)), where P(n,k) is sequence A000027 used as a pairing function.
2
1, 1, 2, 3, 13, 25, 24, 15, 61, 5, 85, 113, 112, 64, 87, 55, 201, 243, 242, 313, 204, 393, 451, 513, 137, 22, 613, 250, 723, 651, 842, 276, 67, 844, 196, 1015, 1107, 657, 196, 1253, 1355, 1020, 1407, 559, 812, 795, 1744, 1864, 833, 2051, 1062, 101, 2181, 1363, 2384, 2524, 597, 2741, 2891, 3045, 3203, 1935, 1756, 1081, 1249, 1938, 3703, 1534, 441
OFFSET
1,3
COMMENTS
For all i, j: a(i) = a(j) => A286385(i) = A286385(j).
LINKS
Eric Weisstein's World of Mathematics, Pairing Function
FORMULA
a(n) = (1/2)*(2 + ((A286448(n)+A286449(n))^2) - A286448(n) - 3*A286449(n)).
a(n) = A286459(A048673(n)).
PROG
(Scheme) (define (A286458 n) (* (/ 1 2) (+ (expt (+ (A286448 n) (A286449 n)) 2) (- (A286448 n)) (- (* 3 (A286449 n))) 2)))
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 14 2017
STATUS
approved