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 A117271 Column 0 of triangle A117270, which is the matrix log of triangle A117269. 3

%I #7 May 09 2014 18:24:15

%S 0,1,2,12,134,2100,42302,1041852,30331814,1019056260,38805685262,

%T 1651676734092,77703508288694,4003868870257620,224255353667365022,

%U 13565588100060643932,881405810330856632774,61218510507062012550180

%N Column 0 of triangle A117270, which is the matrix log of triangle A117269.

%F E.g.f.: A(x) = log( (3-sqrt(5-4*exp(x)))/2 ).

%F a(n) ~ sqrt(10) * n^(n-1) / (6 * exp(n) * (log(5)-2*log(2))^(n-1/2)). - _Vaclav Kotesovec_, Feb 25 2014

%o (PARI) {a(n)=local(C=matrix(n+1,n+1,r,c,if(r>=c,binomial(r-1,c-1))),M=C,L); for(i=1,n+1,M=(M-M^0)^2+C);L=sum(r=1,#M,-(M^0-M)^r/r);return(L[n+1,1])}

%Y Cf. A117269, A117270.

%K nonn

%O 0,3

%A _Paul D. Hanna_, Mar 05 2006

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Last modified September 21 02:47 EDT 2023. Contains 365486 sequences. (Running on oeis4.)