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.

Showing 1-2 of 2 results.

A145367 Lower triangular array, called S1hat(-3), related to partition number array A145366.

Original entry on oeis.org

1, 3, 1, 6, 3, 1, 6, 15, 3, 1, 0, 24, 15, 3, 1, 0, 54, 51, 15, 3, 1, 0, 36, 108, 51, 15, 3, 1, 0, 36, 198, 189, 51, 15, 3, 1, 0, 0, 360, 360, 189, 51, 15, 3, 1, 0, 0, 324, 846, 603, 189, 51, 15, 3, 1, 0, 0, 216, 1296, 1332, 603, 189, 51, 15, 3, 1, 0, 0, 216, 2484, 2754, 2061, 603, 189
Offset: 1

Views

Author

Wolfdieter Lang, Oct 17 2008

Keywords

Comments

If in the partition array M31hat(-3):=A145366 entries belonging to partitions with the same parts number m are summed one obtains this triangle of numbers S1hat(-3). In the same way the signless Stirling1 triangle |A008275| is obtained from the partition array M_2 = A036039.
The first column is [1,3,6,6,0,0,0,...]= A008279(3,n-1), n>=1.

Examples

			Triangle begins:
  [1];
  [3,1];
  [6,3,1];
  [6,15,3,1];
  [0,24,15,3,1];
  ...
		

Crossrefs

Cf. A145368 (row sums).

Formula

a(n,m) = sum(product(S1(-3;j,1)^e(n,m,q,j),j=1..n),q=1..p(n,m)) if n>=m>=1, else 0. Here p(n,m)=A008284(n,m), the number of m parts partitions of n and e(n,m,q,j) is the exponent of j in the q-th m part partition of n. S1(-3,n,1)= A008279(3,n-1) = [1,3,6,6,0,0,0,...], n>=1.

A145371 Row sums of triangle A145370 (S1hat(-4)) and partition array A145359 (M31hat(-4)).

Original entry on oeis.org

1, 5, 17, 57, 129, 433, 1009, 3089, 7697, 20049, 48849, 139729, 317137, 818897, 2040017, 5125329, 12000465, 30811345, 71582929, 179008721, 427693265, 1024611537, 2413499601, 6027416785, 13788615889
Offset: 1

Views

Author

Wolfdieter Lang, Oct 17 2008

Keywords

Crossrefs

Cf. A145359, A145370, A145368 (row sums of triangle A145367).

Formula

a(n) = Sum_{m=1..n} A145370(n,m), n>=1.
Showing 1-2 of 2 results.