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 A154647 #8 May 27 2024 07:16:36 %S A154647 1,2,2,5,22,5,14,178,178,14,41,1308,3446,1308,41,122,9234,52084,52084, %T A154647 9234,122,365,64082,692707,1434812,692707,64082,365,1094,442082, %U A154647 8559030,32285474,32285474,8559030,442082,1094,3281,3048184,101121500,641507528,1151050534,641507528,101121500,3048184,3281 %N A154647 Triangle, T(n, k) = [x^k]( p(x, n) ), where (1/2)*(1-x)^(n+1) * Sum_{j >= 0} ((4*j + 3)^n + (4*j+1)^n )*x^j, read by rows. %H A154647 G. C. Greubel, <a href="/A154647/b154647.txt">Rows n = 0..50 of the triangle, flattened</a> %F A154647 T(n, k) = [x^k]( p(x, n) ), where (1/2)*(1-x)^(n+1) * Sum_{j >= 0} ((4*j + 3)^n + (4*j+1)^n )*x^j. %F A154647 T(n, n-k) = T(n, k). %F A154647 Sum_{k=0..n} T(n, k) = A047053(n) (row sums). %F A154647 T(n, 0) = T(n, n) = A007051(n). - _G. C. Greubel_, May 27 2024 %e A154647 Triangle begins as: %e A154647 1; %e A154647 2, 2; %e A154647 5, 22, 5; %e A154647 14, 178, 178, 14; %e A154647 41, 1308, 3446, 1308, 41; %e A154647 122, 9234, 52084, 52084, 9234, 122; %e A154647 365, 64082, 692707, 1434812, 692707, 64082, 365; %e A154647 1094, 442082, 8559030, 32285474, 32285474, 8559030, 442082, 1094; %t A154647 m=12; p[x_, n_]= (1/2)*(1-x)^(n+1)*Sum[((4*j+3)^n + (4*j+1)^n)*x^j, {j,0,m +2}]; T[n_, k_]:= Coefficient[p[x, n], x, k]; %t A154647 Table[T[n,k], {n,0,m}, {k,0,n}]//Flatten %o A154647 (Magma) %o A154647 m:=12; %o A154647 R<x>:=PowerSeriesRing(Integers(), m+2); %o A154647 p:= func< n,x | (1-x)^(n+1)*(&+[((4*j+3)^n+(4*j+1)^n)/2*x^j: j in [0..m+2]]) >; %o A154647 T:= func< n,k | Coefficient(R!( p(n,x) ), k) >; %o A154647 [T(n,k): k in [0..n], n in [0..m]]; // _G. C. Greubel_, May 27 2024 %o A154647 (SageMath) %o A154647 m=12 %o A154647 def p(x,n): return (1-x)^(n+1)*sum( ((4*j+3)^n +(4*j+1)^n)*x^j for j in range(m+2))/2 %o A154647 def T(n,k): return ( p(x,n) ).series(x, n+1).list()[k] %o A154647 flatten([[T(n,k) for k in range(n+1)] for n in range(m+1)]) # _G. C. Greubel_, May 27 2024 %Y A154647 Cf. A007051, A047053 (row sums), A154646. %K A154647 nonn,tabl %O A154647 0,2 %A A154647 _Roger L. Bagula_, Jan 13 2009 %E A154647 Edited by _G. C. Greubel_, May 27 2024