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Eigensequence of triangle A130534.
7

%I #21 Apr 14 2024 16:48:39

%S 1,1,2,7,36,250,2229,24656,329883,5233837,96907908,2066551242,

%T 50196458429,1375782397859,42203985613593,1438854199059479,

%U 54180508061067099,2241000820010271224,101316373253530824771,4984697039955303538934,265819807417517749652933

%N Eigensequence of triangle A130534.

%C Triangle begins

%C 1;

%C 1, 1;

%C 2, 3, 1;

%C 6, 11, 6, 1;

%C 24, 50, 35, 10, 1;

%C ...

%C Shift the entire triangle down 1 place, with T(0,0) = 1. Let T = the new triangle: (1; 1; 1, 1; 2, 3, 1;...).

%C Sequence A143805 = lim_{n -> infinity} T^n as a vector.

%H Milan Janjic, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL15/Janjic/janjic42.html">Determinants and Recurrence Sequences</a>, Journal of Integer Sequences, 2012, Article 12.3.5. [_N. J. A. Sloane_, Sep 16 2012]

%F a(n) = Sum_{k=0..n-1} (-1)^(n-k-1) * Stirling1(n,k+1) * a(k) for n>0 with a(0)=1 (by definition). - _Paul D. Hanna_, Oct 01 2013

%F E.g.f.: Sum_{n>=0} a(n)*x^n/n! = 1 + Sum_{n>=1} a(n-1)*(-log(1-x))^n/n!. - _Paul D. Hanna_, May 20 2009

%e From _Paul D. Hanna_, May 20 2009: (Start)

%e E.g.f.: A(x) = 1 + x + 2*x^2/2! + 7*x^3/3! + 36*x^4/4! + 250*x^5/5! + ...

%e A(x) = 1 - log(1-x) + log(1-x)^2/2! - 2*log(1-x)^3/3! + 7*log(1-x)^4/4! - 36*log(1-x)^5/5! +- ... (End)

%o (PARI) {a(n)=local(A=[1]);for(i=1,n,A=Vec(serlaplace(1+sum(k=1,#A,A[k]*(-log(1-x+x*O(x^n)))^k/k!))));A[n+1]} \\ _Paul D. Hanna_, May 20 2009

%o (PARI) {Stirling1(n, k)=n!*polcoeff(binomial(x, n), k)}

%o {a(n)=if(n==0, 1, sum(k=0, n-1, (-1)^(n-k-1)*Stirling1(n, k+1)*a(k)))} \\ _Paul D. Hanna_, Oct 01 2013

%Y Cf. A143806.

%K nonn

%O 0,3

%A _Gary W. Adamson_, Sep 01 2008

%E Extended by _Paul D. Hanna_, May 20 2009

%E Offset 0 by _Georg Fischer_, Apr 14 2024