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 A073153 #9 Nov 18 2024 22:30:50 %S A073153 1,1,2,4,5,9,14,18,22,36,56,70,86,100,156,237,293,349,405,461,698, %T A073153 1046,1283,1507,1703,1927,2164,3210,4762,5808,6756,7540,8324,9272, %U A073153 10318,15080,22198,26960,31144,34462,37598,40916,45100,49862,72060,105430,127628 %N A073153 Triangle of numbers relating two sequences A073155 and A073156. %F A073153 Triangle {T(n, k), n >= 0, 0<=k<=n} defined by: T(0, 0)=1, %F A073153 T(n, 0) = A073155(n), T(n, n) = A073156(n), %F A073153 T(n, 0) = T(n-1, n-1) + 2*T(n-2, n-2) + T(n-3, n-3), %F A073153 T(n, k) = Sum_{j=0..k} A073155(j) * A073155(n-j). %e A073153 T(4,0) = T(3,3) + 2*T(2,2) + T(1,1) = 2 + 2*9 + 36 = 56. %e A073153 T(5,2) = A073155(0)*A073155(5) + A073155(1)*A073155(4) + A073155(2)*A073155(3) = 1*237 + 1*56 + 4*14 = 349. %e A073153 Triangle begins: %e A073153 1; %e A073153 1, 2; %e A073153 4, 5, 9; %e A073153 14, 18, 22, 36; %e A073153 56, 70, 86, 100, 156; %e A073153 237, 293, 349, 405, 461, 698; %e A073153 1046, 1283, 1507, 1703, 1927, 2164, 3210; ... %Y A073153 Cf. A073154, A073155, A073156, A073157, A073153. %K A073153 easy,nonn,tabl %O A073153 0,3 %A A073153 _Paul D. Hanna_, Jul 29 2002 %E A073153 Formulas simplified by _Paul D. Hanna_, Nov 26 2012 %E A073153 a(31) onward corrected by _Sean A. Irvine_, Nov 18 2024