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1,3
Numbers n such that n^2 - n is divisible by 19.
Table of n, a(n) for n=1..57.
a(n+1) = Sum_k>=0 {A030308(n,k)*b(k)} with b(0)=1 and b(k)=19*2^(k-1) for k>0. - From Philippe Deléham, Oct 19 2011.
a(n) = a(n-1)+a(n-2)-a(n-3). G.f.: x^2*(1+18*x)/((1-x)^2*(1+x)). - Colin Barker, Apr 09 2012
(MAGMA) [ n : n in [0..600] | n mod 19 eq 0 or n mod 19 eq 1] [From Vincenzo Librandi, Jan 26 2011]
Sequence in context: A007640 A241849 A054304 * A022109 A041730 A041732
Adjacent sequences: A151976 A151977 A151978 * A151980 A151981 A151982
nonn,easy
N. J. A. Sloane, Aug 23 2009
approved