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A286381 Compound filter: a(n) = P(A055881(n), A278236(n)), where P(n,k) is sequence A000027 used as a pairing function. 2
2, 5, 16, 12, 67, 9, 16, 23, 436, 80, 1771, 18, 67, 80, 1771, 668, 16111, 48, 277, 302, 7141, 2630, 64621, 14, 16, 23, 436, 80, 1771, 31, 436, 467, 21946, 1832, 87991, 94, 1771, 1832, 87991, 16292, 793171, 328, 7141, 7262, 352381, 64982, 3173941, 25, 67, 80, 1771, 668, 16111, 94, 1771, 1832, 87991, 16292, 793171, 706, 16111, 16292, 793171, 405452, 19841851 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10080

Eric Weisstein's World of Mathematics, Pairing Function

Index entries for sequences related to factorial base representation

FORMULA

a(n) = (1/2)*(2 + ((A055881(n)+A278236(n))^2) - A055881(n) - 3*A278236(n)).

PROG

(Scheme) (define (A286381 n) (* (/ 1 2) (+ (expt (+ (A055881 n) (A278236 n)) 2) (- (A055881 n)) (- (* 3 (A278236 n))) 2)))

CROSSREFS

Cf. A000027, A055881, A278236, A286382, A286143.

Sequence in context: A111790 A248125 A297473 * A286382 A127580 A098048

Adjacent sequences:  A286378 A286379 A286380 * A286382 A286383 A286384

KEYWORD

nonn

AUTHOR

Antti Karttunen, May 08 2017

STATUS

approved

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Last modified June 25 06:26 EDT 2019. Contains 324347 sequences. (Running on oeis4.)