cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A364708 Triangle of coefficient of the series reversion in t of the power series (exp(log(1+t*x)/x)-1)*exp(-t) as an e.g.f.

Original entry on oeis.org

1, 1, 1, 2, 6, 1, 6, 35, 22, 1, 24, 225, 310, 65, 1, 120, 1624, 3885, 1975, 171, 1, 720, 13132, 47929, 45080, 10367, 420, 1, 5040, 118124, 606060, 909489, 409416, 48034, 988, 1, 40320, 1172700, 7995455, 17445645, 13033398, 3152520, 204423, 2259, 1, 362880, 12753576, 110917400, 330281930, 369520305, 153751773, 21587950, 819120, 5065, 1
Offset: 1

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Author

Paul Laubie, Oct 20 2023

Keywords

Comments

T(n,k) is also the dimension of the operad FMan in arity n with k commutative products.
The sum of each row is n^(n-1).

Examples

			Triangle T(n,k) begins:
n\k  0     1    2   3   4  ...
1    1;
2    1,    1;
3    2,    6,   1;
4    6,   35,  22,  1;
5   24,  225, 310, 65,  1;
...
		

Crossrefs

Column k=0 is A000142(n-1).
Row sums are A000169.
Seems related to a signed version of A079510.

Programs

  • PARI
    T(n) = my(x='x+O('x^(n+1))); [Vecrev(p) | p<-Vec(serlaplace( serreverse((exp(log(1+x*y)/y)-1)*exp(-x) )))]
    {my(A=T(10)); for(n=1, #A, print(A[n]))} \\ Andrew Howroyd, Oct 20 2023

Formula

T(n,0) = (n-1)!.
T(n,n-1) = 1.