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%I #5 May 14 2017 15:55:26
%S 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,
%T 313,33,365,1,421,1,481,72,545,13,613,1,685,143,761,1,841,1,925,86,
%U 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
%N 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.
%H Antti Karttunen, <a href="/A286457/b286457.txt">Table of n, a(n) for n = 1..10000</a>
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PairingFunction.html">Pairing Function</a>
%F a(1) = 0 and for n > 1, a(n) = (1/2)*(2 + ((A078898(n)+A246277(n))^2) - A078898(n) - 3*A246277(n)).
%o (Scheme) (define (A286457 n) (if (= 1 n) 0 (* (/ 1 2) (+ (expt (+ (A078898 n) (A246277 n)) 2) (- (A078898 n)) (- (* 3 (A246277 n))) 2))))
%Y Cf. A000027, A078898, A246277, A280492.
%K nonn
%O 1,4
%A _Antti Karttunen_, May 14 2017