login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Triangle of compositions with a total that is no more than n into exactly k parts each no more than k.
2

%I #7 Mar 30 2012 18:51:39

%S 1,1,1,1,3,1,1,4,4,1,1,4,10,5,1,1,4,17,15,6,1,1,4,23,35,21,7,1,1,4,26,

%T 66,56,28,8,1,1,4,27,106,126,84,36,9,1,1,4,27,150,247,210,120,45,10,1,

%U 1,4,27,190,432,462,330,165,55,11,1,1,4,27,221,687,918,792,495,220,66

%N Triangle of compositions with a total that is no more than n into exactly k parts each no more than k.

%H <a href="/index/Com#comp">Index entries for sequences related to compositions</a>

%F T(n, k) =a(n-1, k)+A077227(n, k). If n>=k^2, T(n, k)=n^n. If k<=n<2k, T(n, k)=C(n, k).

%e Rows start: 1; 1,1; 1,3,1; 1,4,4,1; 1,4,10,5,1; 1,4,17,15,6,1; 1,4,23,35,21,7,1; etc. T(6,3)=17 since compositions with 3 parts each no more than 3 and a total no more than 6 are: 1+1+1, 1+1+2, 1+1+3, 1+2+1, 1+2+2, 1+2+3, 1+3+1, 1+3+2, 2+1+1, 2+1+2, 2+1+3, 2+2+1, 2+2+2, 2+3+1, 3+1+1, 3+1+2 and 3+2+1.

%Y Rows eventually start like A000312. Central diagonal is A001700. Right hand side and central diagonal is like right hand side of A007318. Cf. A077227.

%K nonn,tabl

%O 0,5

%A _Henry Bottomley_, Oct 30 2002