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 A383155 #15 Apr 23 2025 13:24:30
%S A383155 0,-1,58,-180,-1304,-2920,1008,34496,163840,525312,1285120,2241536,
%T A383155 1124352,-12113920,-72052736,-282378240,-924581888,-2699493376,
%U A383155 -7201751040,-17666670592,-39507722240,-77918109696,-121883328512,-78622228480,453588811776,2904974950400,11885785120768
%N A383155 a(n) = Sum_{k=0..n} k^6 * (-1)^k * 3^(n-k) * binomial(n,k).
%H A383155 Vincenzo Librandi, <a href="/A383155/b383155.txt">Table of n, a(n) for n = 0..700</a>
%F A383155 a(n) = 2^(n-6) * (-4368*n + 7290*n^2 - 3555*n^3 + 645*n^4 - 45*n^5 + n^6).
%t A383155 Table[Sum[(k^6*(-1)^k*3^(n-k))*Binomial[n,k],{k,0,n}],{n,0,30}] (* _Vincenzo Librandi_, Apr 23 2025 *)
%o A383155 (PARI) a(n) = 2^(n-6)*(-4368*n+7290*n^2-3555*n^3+645*n^4-45*n^5+n^6);
%o A383155 (Magma) [&+[k^6 * (-1)^k * 3^(n-k) * Binomial(n,k): k in [0..n]]: n in [0..29]]; // _Vincenzo Librandi_, Apr 23 2025
%Y A383155 Cf. A001787, A178987, A383150, A383151, A383152.
%K A383155 sign,easy
%O A383155 0,3
%A A383155 _Seiichi Manyama_, Apr 18 2025