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 A144880 #10 Aug 29 2019 17:10:55 %S A144880 1,3,1,12,3,1,60,12,9,3,1,360,60,36,12,9,3,1,2520,360,180,144,60,36, %T A144880 27,12,9,3,1,20160,2520,1080,720,360,180,144,108,60,36,27,12,9,3,1, %U A144880 181440,20160,7560,4320,3600,2520,1080,720,540,432,360,180,144,108,81,60,36,27 %N A144880 Partition number array, called M31hat(3). %C A144880 Each partition of n, ordered as in Abramowitz-Stegun (A-St order; for the reference see A134278), is mapped to a nonnegative integer a(n,k) =: M31hat(3;n,k) with the k-th partition of n in A-St order. %C A144880 The sequence of row lengths is A000041 (partition numbers) [1, 2, 3, 5, 7, 11, 15, 22, 30, 42,...]. %C A144880 This is the third (K=3) member of a family of partition number arrays: A107106, A134133,... %H A144880 W. Lang, <a href="/A144880/a144880.txt">First 10 rows of the array and more.</a> %H A144880 W. Lang, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL12/Lang/lang.html">Combinatorial Interpretation of Generalized Stirling Numbers</a>, J. Int. Seqs. Vol. 12 (2009) 09.3.3. %F A144880 a(n,k)= product(|S1(3;j,1)|^e(n,k,j),j=1..n) with |S1(3;n,1)|= A046089(1,n) = [1,3,12,60,...], n>=1 and the exponent e(n,k,j) of j in the k-th partition of n in the A-St ordering of the partitions of n. %e A144880 [1];[3,1];[12,3,1];[60,12,9,3,1];[360,60,36,12,9,3,1];... %e A144880 a(4,3)= 9 = |S1(3;2,1)|^2. The relevant partition of 4 is (2^2). %Y A144880 A144882 (row sums). %Y A144880 A134133 (M31hat(2) array). A144885 (M31hat(4) array). %K A144880 nonn,easy,tabf %O A144880 1,2 %A A144880 _Wolfdieter Lang_ Oct 09 2008