A145362 Lower triangular array S1hat(-1) read by rows, related to partition number array A145361.
1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1
Offset: 1
Examples
Triangle begins: [1]; [1,1]; [0,1,1]; [0,1,1,1]; [0,0,1,1,1]; [0,0,1,1,1,1]; ...
Links
- Wolfdieter Lang, First 10 rows of the array and more.
- Louis Comtet, Advanced Combinatorics, Reidel (1974).
- Wolfdieter Lang, Combinatorial Interpretation of Generalized Stirling Numbers, J. Int. Seqs. Vol. 12 (2009) 09.3.3.
Crossrefs
Programs
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PARI
T(n, k) = n<=2*k; \\ Jinyuan Wang, Jan 19 2025
Formula
T(n,m) = Sum_{q=1..p(n,m)} Product_{j=1..n} S1(-1;j,1)^e(n,m,q,j) 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(-1;n,1) = A008279(1,n-1) = [1,1,0,0,0,...], n>=1.
The triangle starts in row n with ceiling(n/2) - 1 zeros, and is 1 otherwise. - Wolfdieter Lang, Aug 03 2023
G.f.: 1/((1-u*t)*(1-u*t^2)). [Comtet page 97 [2c]]. - R. J. Mathar, May 27 2025
Comments