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%I #5 Oct 01 2013 17:57:55
%S 5,13,5,41,61,17,113,29,181,17,53,313,73,421,37,109,613,137,761,29,37,
%T 1013,17,1201,1301,281,89,13,1741,1861,397,2113,449,2381,2521,41,97,
%U 593,3121,193,53,3613,757,233,101,173,4513,941,29,5101,1061,149,229,457,101
%N Greatest prime factor of n^2 + (n+1)^2.
%e 2*7^2 - 2*7 + 1 = 85 = 5*17, so a(7)=17.
%o (PARI) xnpym1n(m) = { for(n=1,m, y = n^2+(n+1)^2; f = factor(y); l = length(component(f,1)); v = component(component(f,1),l); print1(v","); ) }
%Y Cf. A027861, A027862.
%Y Equals A006530(A001844(n-1)).
%K easy,nonn
%O 2,1
%A _Cino Hilliard_, Dec 31 2003
%E Edited by _Ray Chandler_, Jan 03 2004
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