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 A364911 #10 Jan 11 2024 22:56:54 %S A364911 1,1,1,1,2,1,1,3,1,2,1,4,2,3,2,1,5,2,5,3,3,1,6,3,8,4,4,4,1,7,3,11,6,6, %T A364911 6,5,1,8,4,14,9,8,10,7,6,1,9,4,19,11,11,14,11,9,8,1,10,5,23,14,15,21, %U A364911 15,14,11,10,1,11,5,28,17,19,28,22,20,17,15,12 %N A364911 Triangle read by rows where T(n,k) is the number of integer partitions with sum <= n and with distinct parts summing to k. %C A364911 Also the number of ways to write any number up to n as a positive linear combination of a strict integer partition of k. %H A364911 Andrew Howroyd, <a href="/A364911/b364911.txt">Table of n, a(n) for n = 0..1325</a> (rows 0..50) %F A364911 G.f.: A(x,y) = (1/(1 - x)) * Product_{k>=1} (1 - y^k + y^k/(1 - x^k)). - _Andrew Howroyd_, Jan 11 2024 %e A364911 Triangle begins: %e A364911 1 %e A364911 1 1 %e A364911 1 2 1 %e A364911 1 3 1 2 %e A364911 1 4 2 3 2 %e A364911 1 5 2 5 3 3 %e A364911 1 6 3 8 4 4 4 %e A364911 1 7 3 11 6 6 6 5 %e A364911 1 8 4 14 9 8 10 7 6 %e A364911 1 9 4 19 11 11 14 11 9 8 %e A364911 1 10 5 23 14 15 21 15 14 11 10 %e A364911 1 11 5 28 17 19 28 22 20 17 15 12 %e A364911 1 12 6 34 21 22 40 28 28 24 24 17 15 %e A364911 1 13 6 40 25 27 50 38 37 34 35 27 22 18 %e A364911 1 14 7 46 29 32 65 49 50 43 51 38 35 26 22 %e A364911 1 15 7 54 33 38 79 62 63 59 68 55 50 41 32 27 %e A364911 Row n = 5 counts the following partitions: %e A364911 . 1 2 3 4 5 %e A364911 1+1 2+2 1+2 1+3 1+4 %e A364911 1+1+1 1+1+2 1+1+3 2+3 %e A364911 1+1+1+1 1+1+1+2 %e A364911 1+1+1+1+1 1+2+2 %e A364911 Row n = 5 counts the following positive linear combinations: %e A364911 . 1*1 1*2 1*3 1*4 1*5 %e A364911 2*1 2*2 1*2+1*1 1*3+1*1 1*3+1*2 %e A364911 3*1 1*2+2*1 1*3+2*1 1*4+1*1 %e A364911 4*1 1*2+3*1 %e A364911 5*1 2*2+1*1 %t A364911 Table[Length[Select[Array[IntegerPartitions,n+1,0,Join],Total[Union[#]]==k&]],{n,0,9},{k,0,n}] %o A364911 (PARI) T(n)={[Vecrev(p) | p<-Vec(prod(k=1, n, 1 - y^k + y^k/(1 - x^k), 1/(1 - x) + O(x*x^n)))]} %o A364911 { my(A=T(10)); for(n=1, #A, print(A[n])) } \\ _Andrew Howroyd_, Jan 11 2024 %Y A364911 Column n = k is A000009. %Y A364911 Column k = 0 is A000012. %Y A364911 Column k = 1 is A000027. %Y A364911 Row sums are A000070. %Y A364911 Column k = 2 is A008619. %Y A364911 Columns are partial sums of columns of A116861. %Y A364911 Column k = 3 appears to be the partial sums of A137719. %Y A364911 Diagonal n = 2k is A364910. %Y A364911 A000041 counts integer partitions, strict A000009. %Y A364911 A008284 counts partitions by length, strict A008289. %Y A364911 A114638 counts partitions where (length) = (sum of distinct parts). %Y A364911 A116608 counts partitions by number of distinct parts. %Y A364911 A364350 counts combination-free strict partitions, complement A364839. %Y A364911 Cf. A002865, A066328, A179009, A236912, A237113, A237667, A364912, A364913, A364915, A364916, A365002, A365004. %K A364911 nonn,tabl %O A364911 0,5 %A A364911 _Gus Wiseman_, Aug 27 2023