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 A286457 Compound filter: a(n) = P(A078898(n), A246277(n)), with a(1) = 0, where P(n,k) is sequence A000027 used as a pairing function. 2
 0, 1, 1, 5, 1, 13, 1, 25, 5, 41, 1, 61, 1, 85, 13, 113, 1, 145, 1, 181, 32, 221, 1, 265, 5, 313, 33, 365, 1, 421, 1, 481, 72, 545, 13, 613, 1, 685, 143, 761, 1, 841, 1, 925, 86, 1013, 1, 1105, 5, 1201, 219, 1301, 1, 1405, 32, 1513, 335, 1625, 1, 1741, 1, 1861, 201, 1985, 60, 2113, 1, 2245, 447, 2381, 1, 2521, 1, 2665, 223, 2813, 13, 2965, 1, 3121, 224, 3281 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 LINKS Antti Karttunen, Table of n, a(n) for n = 1..10000 Eric Weisstein's World of Mathematics, Pairing Function FORMULA a(1) = 0 and for n > 1, a(n) = (1/2)*(2 + ((A078898(n)+A246277(n))^2) - A078898(n) - 3*A246277(n)). PROG (Scheme) (define (A286457 n) (if (= 1 n) 0 (* (/ 1 2) (+ (expt (+ (A078898 n) (A246277 n)) 2) (- (A078898 n)) (- (* 3 (A246277 n))) 2)))) CROSSREFS Cf. A000027, A078898, A246277, A280492. Sequence in context: A094049 A286254 A322664 * A327766 A147348 A081224 Adjacent sequences:  A286454 A286455 A286456 * A286458 A286459 A286460 KEYWORD nonn AUTHOR Antti Karttunen, May 14 2017 STATUS approved

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Last modified May 16 22:18 EDT 2021. Contains 343957 sequences. (Running on oeis4.)