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 A109390 #8 Sep 08 2013 13:30:45 %S A109390 1,1,1,1,1,1,3,1,1,1,1,1,2,5,2,1,5,5,1,1,2,1,1,1,3,7,3,3,12,12,3,1,7, %T A109390 12,7,1,1,3,3,1,1,1,4,9,4,6,22,22,6,4,22,36,22,4,1,9,22,22,9,1,1,1,5, %U A109390 11,5,10,35,35,10,10,50,80,50,10,5,35,80,80,35,5,1,11,35,50 %N A109390 Entries in 3-dimensional solid related to Prouhet-Tarry problem. %C A109390 Entries of slices [n,1] in A109672, read by rows. %C A109390 Slice [n,0] gives A046816, slice [0,k] gives A109649, slice [n,n] gives A109673, slice [1,k] gives A109393. %F A109390 Sum of terms in 2D slice [n, 1] is 3^(n+1). %e A109390 Slice [0,1]: %e A109390 ... 1 1 ... %e A109390 .... 1 .... %e A109390 Slice [1,1]: %e A109390 ... 1 1 ... %e A109390 .. 1 3 1 ... %e A109390 ... 1 1 ... %e A109390 Slice [2,1]: %e A109390 .... 1 1 .... %e A109390 ... 2 5 2 ... %e A109390 .. 1 5 5 1 ... %e A109390 ... 1 2 1 ... %e A109390 Slice [3,1]: %e A109390 ..... 1 1 ..... %e A109390 .... 3 7 3 .... %e A109390 ... 3 12 12 3 ... %e A109390 .. 1 7 12 7 1 ... %e A109390 ... 1 3 3 1 ... %e A109390 Slice [4,1]: %e A109390 ...... 1 1 ...... %e A109390 ..... 4 9 4 ..... %e A109390 .... 6 22 22 6 .... %e A109390 ... 4 22 36 22 4 ... %e A109390 .. 1 9 22 22 9 1 ... %e A109390 ... 1 4 6 4 1 ... %e A109390 Slice [5,1]: %e A109390 ....... 1 1 ....... %e A109390 ...... 5 11 5 ...... %e A109390 ..... 10 35 35 10 ..... %e A109390 .... 10 50 80 50 10 .... %e A109390 ... 5 35 80 80 35 5 ... %e A109390 .. 1 11 35 50 35 11 1 ... %e A109390 ... 1 5 10 10 5 1 ... %Y A109390 Cf. A109393. %K A109390 nonn,tabf,easy %O A109390 0,7 %A A109390 _Philippe Deléham_, Aug 26 2005