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.
%I A232539 #26 May 27 2025 10:21:47 %S A232539 1,0,1,0,1,1,0,1,1,1,0,1,2,1,1,0,0,2,2,1,1,0,0,2,3,2,1,1,0,0,1,3,3,2, %T A232539 1,1,0,0,1,3,4,3,2,1,1,0,0,0,3,4,4,3,2,1,1,0,0,0,2,5,5,4,3,2,1,1,0,0, %U A232539 0,1,4,6,5,4,3,2,1,1,0,0,0,1,4,6,7,5,4,3,2,1,1 %N A232539 Triangle read by rows: T(n,k) = number of partitions of n into at most four parts in which the largest part is equal to k, 0 <= k <= n. %C A232539 Also number of partitions of n into k parts with parts in the range 1..4. %H A232539 Louis Comtet, <a href="https://doi.org/10.1007/978-94-010-2196-8">Advanced Combinatorics</a>, Reidel (1974). %F A232539 G.f.: 1/((1-u*t)*(1-u*t^2)*(1-u*t^3)*(1-u*t^4)). - [Comtet p. 97 [2c]]. - _R. J. Mathar_, May 27 2025 %e A232539 Triangle T{n,k} begins: %e A232539 1; %e A232539 0, 1; %e A232539 0, 1, 1; %e A232539 0, 1, 1, 1; %e A232539 0, 1, 2, 1, 1; %e A232539 0, 0, 2, 2, 1, 1; %e A232539 0, 0, 2, 3, 2, 1, 1; %e A232539 0, 0, 1, 3, 3, 2, 1, 1; %e A232539 0, 0, 1, 3, 4, 3, 2, 1, 1; %e A232539 0, 0, 0, 3, 4, 4, 3, 2, 1, 1; %e A232539 ... %p A232539 maxp := 4 : %p A232539 gf := 1/mul(1-u*t^i,i=1..maxp) : %p A232539 for n from 0 to 13 do %p A232539 for m from 0 to n do %p A232539 coeftayl(gf,t=0,n) ; %p A232539 coeftayl(%,u=0,m) ; %p A232539 printf("%d ",%); %p A232539 end do: %p A232539 printf("\n") ; %p A232539 end do: # _R. J. Mathar_, May 27 2025 %Y A232539 Cf. A001400 (row sums), A219237, A233292 (row partial sums), A145362 (parts <=2), A339884 (parts <=3). %K A232539 nonn,tabl %O A232539 0,13 %A A232539 _L. Edson Jeffery_, Jan 02 2014