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 A338586 #16 Feb 16 2025 08:34:00 %S A338586 1,1,0,0,0,1,2,5,5,20,35,75,154,336,730,1570,3394,7339,16085,35015, %T A338586 76269,164821,359704,782004,1696804,3668860,7953962,17184203,37093184, %U A338586 79825297,171824175,368838299,790404448,1690297309,3610816466,7696144659,16374004711,34766160358 %N A338586 Number of partitions of the n-th tetrahedral number into exactly n positive tetrahedral numbers. %H A338586 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TetrahedralNumber.html">Tetrahedral Number</a> %H A338586 <a href="/index/Ps#pyramidal_numbers">Index to sequences related to pyramidal numbers</a> %H A338586 <a href="/index/Par#part">Index entries for sequences related to partitions</a> %F A338586 a(n) = [x^A000292(n) y^n] Product_{j>=1} 1 / (1 - y*x^A000292(j)). %e A338586 The 6th tetrahedral number is 56 and 56 = 1 + 1 + 4 + 10 + 20 + 20 = 4 + 4 + 4 + 4 + 20 + 20, so a(6) = 2. %Y A338586 Cf. A000292, A068980, A298269, A298857, A303170, A307643, A338585, A338778. %K A338586 nonn %O A338586 0,7 %A A338586 _Ilya Gutkovskiy_, Nov 08 2020