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A100236 Main diagonal of triangle A100235. 4

%I #3 Mar 30 2012 18:36:44

%S 1,4,26,139,726,3774,19601,101784,528526,2744419,14250626,73997554,

%T 384238401,1995189564,10360186226,53796120699,279340789726,

%U 1450500069334,7531841136401,39109705751344,203080369893126

%N Main diagonal of triangle A100235.

%F a(n) = 5*a(n-1) + a(n-2) + 5 for n>1, with a(0)=1, a(1)=4. G.f.: Sum_{n>=1} a(n)*x^n/n = log((1-x)/(1-5*x-x^2)).

%o (PARI) a(n)=if(n==0,1,n*polcoeff(log((1-x)/(1-5*x-x^2)+x*O(x^n)),n))

%Y Cf. A100233, A100235.

%Y Equals A087130(n) - 1.

%K nonn

%O 0,2

%A _Paul D. Hanna_, Nov 30 2004

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Last modified March 2 02:30 EST 2024. Contains 370447 sequences. (Running on oeis4.)