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%I #8 Apr 05 2019 05:32:23
%S 6,66,114,162,5466,1026,1926,606,5466,1746,29154,522,3838386,27066,
%T 4302,1254,92886,3246,2466,1578,113573466,1026,129474,9402,280201746,
%U 66,236646,231006,6808626,122826,545646,1422,9003546,66666,10242,2874,418384938,3344058
%N a(n) = A051717(3n) + A051717(3n+1) + A051717(3n+2).
%C All terms are multiples of 6.
%C The first differences are 60, 48, 48, 5304, -4440, ... Apparently (checked for the first 700 entries) these are multiples of 12.
%p C:=proc(n) if n=0 then RETURN(1); fi; if n mod 2 = 0 then RETURN(bernoulli(n)+bernoulli(n-1)); else RETURN(-bernoulli(n)-bernoulli(n-1)); fi; end:
%p A051717 := proc(n) denom(C(n)) ; end: A153087 := proc(n) A051717(3*n)+A051717(3*n+1)+A051717(3*n+2) ; end: seq(A153087(n),n=0..120) ; # _R. J. Mathar_, Sep 07 2009
%Y Cf. A051717, A140812.
%K nonn
%O 0,1
%A _Paul Curtz_, Dec 18 2008
%E Extended by _R. J. Mathar_, Sep 07 2009