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 A218539 #21 Nov 07 2012 13:53:27 %S A218539 0,1,20,21,24,153,240,241,289,304,324,370,371,407,440,441,593,739, %T A218539 2167,2284,2348,2484,2583,2860,2861,3009,3029,3093,3249,4288,5859, %U A218539 6888,7996,9898 %N A218539 Numbers that are equal to the sum of the uniform platonic polyhedral (figurate) numbers (tetrahedral, cubic, octahedral, dodecahedral, or icosahedral) on each of their digits. %C A218539 153, 370, 371, and 407 are well known with regard to the cubic numbers. %e A218539 The octahedral numbers are represented by the formula, y(x)=(2x^3+x)/3; apply this formula to each of the digits in a(18)=739, i.e., y(7)=231, y(3)=19, y(9)=489; sum=739; the dodecahedral numbers are represented by the formula, y(x)=x(3x-1)(3x-2)/2; apply this formula to each of the digits in a(34)=9898, i.e., y(9)=2725, y(8)=2024; y(9)=2725, y(8)=2024; sum=9898. %Y A218539 Cf. A005188, A007532, A036057. %K A218539 nonn,base %O A218539 1,3 %A A218539 _Thomas S. Pedigo_, Nov 01 2012