login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

A108041
Triangle of numbers {a(n,k), n >= 0, 0<=k<=n} defined by a(0,0)=1, a(n,0)=a(n-1,n-1), a(n,k)=a(n,k-1) + Sum_{i=0..k-1} a(n-1,i).
4
1, 1, 2, 2, 3, 7, 7, 9, 19, 42, 42, 49, 100, 210, 443, 443, 485, 977, 2005, 4120, 8473, 8473, 8916, 17874, 36240, 73508, 149131, 302615, 302615, 311088, 622619, 1254196, 2526758, 5090784, 10257191, 20667866, 20667866, 20970481, 41949435, 84210401, 169052379
OFFSET
0,3
EXAMPLE
1; 1,2; 2,3,7; 7,9,19,42; 42,49,100,210,443; ...
MAPLE
f := proc(n, k) local i, t1; option remember; if n=0 and k=0 then 1 elif k=0 then f(n-1, n-1) else add(f(n, i), i=0..k-1) +f(n-1, k-1); fi: end;
CROSSREFS
Borders give A108042. Row sums are A108043. Cf. A011971.
Sequence in context: A068519 A342848 A339826 * A376348 A259254 A095017
KEYWORD
tabl,nonn
AUTHOR
N. J. A. Sloane, Jun 01 2005
STATUS
approved

pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.


Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy