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 A100149 #20 Aug 05 2025 13:35:20 %S A100149 1,24,106,284,595,1076,1764,2696,3909,5440,7326,9604,12311,15484, %T A100149 19160,23376,28169,33576,39634,46380,53851,62084,71116,80984,91725, %U A100149 103376,115974,129556,144159,159820,176576,194464,213521,233784,255290,278076,302179,327636 %N A100149 Structured small rhombicubeoctahedral numbers. %H A100149 Vincenzo Librandi, <a href="/A100149/b100149.txt">Table of n, a(n) for n = 1..5000</a> %H A100149 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1). %F A100149 a(n) = (1/6)*(37*n^3 - 45*n^2 + 14*n). %F A100149 G.f.: x*(1 + 20*x + 16*x^2)/(1-x)^4. - _Colin Barker_, Jan 19 2012 %F A100149 From _Elmo R. Oliveira_, Aug 05 2025: (Start) %F A100149 E.g.f.: exp(x)*x*(37*x^2 + 66*x + 6)/6. %F A100149 a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n > 4. (End) %o A100149 (Magma) [(1/6)*(37*n^3-45*n^2+14*n): n in [1..40]]; // _Vincenzo Librandi_, Jul 19 2011 %Y A100149 Cf. A100148, A100150 for adjacent structured Archimedean solids; and A100145 for more on structured polyhedral numbers. %K A100149 nonn,easy %O A100149 1,2 %A A100149 James A. Record (james.record(AT)gmail.com), Nov 07 2004