The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A109153 Column 0 of triangle A109152. 5
 1, 1, 2, 6, 22, 94, 450, 2366, 13450, 81802, 527826, 3590294, 25609782, 190753502, 1478339866, 11884997478, 98859026322, 848881803218, 7509881820930, 68330806392070, 638444805545622, 6117166765086366, 60028033370994386 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Triangular matrix T=A109152 satisfies: T(n,k) = [T^2](n-1,k) for n>k+1>=1, with T(n,n) = 1 and T(n+1,n) = n+1 for n>=0. LINKS Table of n, a(n) for n=0..22. FORMULA T^(m+1) = SHIFT_UP(T^m - T^(m-1)) - D*T^(m-1) for all m where diagonal matrix D = [0, 1, 2, 3, ...] and SHIFT_UP shifts each column up 1 row. PROG (PARI) {a(n)=local(M=matrix(n+1, n+1)); M=M^0; for(i=1, n, M=matrix(n+1, n+1, r, c, if(r>=c, if(r==c, 1, if(r==c+1, c, (M^2)[r-1, c]))))); return(M[n+1, 1])} CROSSREFS Cf. A109152 (triangle), A109154 (column 1), A109155 (column 2), A109156 (row sums). Sequence in context: A317652 A150274 A109317 * A030453 A001861 A049526 Adjacent sequences: A109150 A109151 A109152 * A109154 A109155 A109156 KEYWORD nonn AUTHOR Paul D. Hanna, Jun 20 2005 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 16 07:19 EDT 2024. Contains 373423 sequences. (Running on oeis4.)