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 A343008 #10 Apr 25 2021 23:07:25 %S A343008 28,27,117,260,727,1857,4908,12803,33565,87828,229983,602057,1576252, %T A343008 4126635,10803717,28284452,74049703,193864593,507544140,1328767763, %U A343008 3478759213,9107509812,23843770287,62423800985,163427632732,427859097147,1120149658773 %N A343008 a(n) = F(n+5) * F(n+2) - 12 * (-1)^n where F(n) = A000045(n) are the Fibonacci numbers. %C A343008 First differences of A341928. %C A343008 Second differences of A341208. %C A343008 Third differences of A338225. %C A343008 Fourth differences of A226205. %C A343008 Fourth differences between the areas of consecutive rectangles with side lengths F(n+3) and F(n). %C A343008 Twice the fourth differences between the areas of consecutive deltoids with cross lengths F(n+3) and F(n). %C A343008 Twice the fourth differences between the areas of consecutive triangles with the height and base length are F(n+3) and F(n). %D A343008 B. Muslu, Sayılar ve Bağlantılar, Luna, 2021, p. 52. %H A343008 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (2,2,-1). %F A343008 a(n) = F(n+5) * F(n+2) - 12 * (-1)^n. %F A343008 G.f.: x*(28 - 29*x + 7*x^2)/(1 - 2*x - 2*x^2 + x^3). %e A343008 For n = 2, a(2) = F(2+5) * F(2+2) - 12 * (-1)^2 = 13 * 3 - 12 = 27. %t A343008 a[n_]:=Fibonacci[n+5]*Fibonacci[n+2]-12(-1)^n %t A343008 Array[a,30] (* _Giorgos Kalogeropoulos_, Apr 02 2021 *) %Y A343008 Cf. A000045, A226205, A338225, A341208, A341928. %K A343008 nonn %O A343008 1,1 %A A343008 _Burak Muslu_, Apr 02 2021