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Triangle read by rows: the exponential almost-Riordan array ( exp(x/(1-x)) | 1/(1-x), x ).
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%I #13 Jul 28 2024 03:56:46

%S 1,1,1,3,1,1,13,2,2,1,73,6,6,3,1,501,24,24,12,4,1,4051,120,120,60,20,

%T 5,1,37633,720,720,360,120,30,6,1,394353,5040,5040,2520,840,210,42,7,

%U 1,4596553,40320,40320,20160,6720,1680,336,56,8,1,58941091,362880,362880,181440,60480,15120,3024,504,72,9,1

%N Triangle read by rows: the exponential almost-Riordan array ( exp(x/(1-x)) | 1/(1-x), x ).

%H Y. Alp and E. G. Kocer, <a href="https://doi.org/10.1007/s00025-024-02193-5">Exponential Almost-Riordan Arrays</a>, Results Math 79, 173 (2024). See page 13.

%F T(n,0) = n! * [x^n] exp(x/(1-x)); T(n,k) = (n-1)!/(k-1)! * [x^(n-1)] 1/(1-x)*x^(k-1).

%F T(n,3) = A001710(n-1) for n > 2.

%F T(n,4) = A001715(n-1) for n > 3.

%F T(n,5) = A001720(n-1) for n > 4.

%F T(n,6) = A001725(n-1) for n > 5.

%F T(n,7) = A001730(n-1) for n > 6.

%F T(n,8) = A049388(n-8) for n > 7.

%F T(n,9) = A049389(n-9) for n > 8.

%F T(n,10) = A049398(n-10) for n > 9.

%F T(n,11) = A051431(n-11) for n > 10.

%e The triangle begins:

%e 1;

%e 1, 1;

%e 3, 1, 1;

%e 13, 2, 2, 1;

%e 73, 6, 6, 3, 1;

%e 501, 24, 24, 12, 4, 1;

%e 4051, 120, 120, 60, 20, 5, 1;

%e ...

%t T[n_,0]:=n!SeriesCoefficient[Exp[x/(1-x)],{x,0,n}]; T[n_,k_]:=(n-1)!/(k-1)!SeriesCoefficient[1/(1-x)*x^(k-1),{x,0,n-1}]; Table[T[n,k],{n,0,10},{k,0,n}]//Flatten

%Y Cf. A000142, A000262 (k=0), A001710, A001715, A001720, A001725, A001730, A049388, A049389, A049398, A051431.

%Y Triangle A094587 with 1st column A000262.

%K nonn,tabl

%O 0,4

%A _Stefano Spezia_, May 26 2024