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 A135224 #14 Mar 27 2022 19:01:55 %S A135224 1,3,1,5,3,1,9,7,4,1,17,15,11,5,1,33,31,26,16,6,1,65,63,57,42,22,7,1, %T A135224 129,127,120,99,64,29,8,1,257,255,247,219,163,93,37,9,1,513,511,502, %U A135224 466,382,256,130,46,10,1 %N A135224 Triangle A103451 * A007318 * A000012, read by rows. T(n, k) for 0 <= k <= n. %C A135224 Row sums = A132750: (1, 4, 9, 21, 49, 113, ...). %C A135224 Left border = A083318: (1, 3, 5, 9, 17, 33, ...). %H A135224 G. C. Greubel, <a href="/A135224/b135224.txt">Rows n = 0..100 of triangle, flattened</a> %F A135224 T(n, k) = A103451(n,k) * A007318(n,k) * A000012(n,k) as infinite lower triangular matrices. %F A135224 T(n, k) = Sum_{j=0..n} binomial(n, k+j), with T(0,0) = 1 and T(n,0) = 2^n + 1. - _G. C. Greubel_, Nov 20 2019 %F A135224 T(n, k) = binomial(n, k)*hypergeom([1, k-n], [k+1], -1) - binomial(n, k+n+1)* hypergeom([1, k+1], [k+n+2], -1) + 0^k - 0^n. - _Peter Luschny_, Nov 20 2019 %e A135224 First few rows of the triangle: %e A135224 1; %e A135224 3, 1; %e A135224 5, 3, 1; %e A135224 9, 7, 4, 1; %e A135224 17, 15, 11, 5, 1; %e A135224 33, 31, 26, 16, 6, 1; %e A135224 65, 63, 57, 42, 22, 7, 1; %e A135224 ... %p A135224 T:= proc(n, k) option remember; %p A135224 if k=0 and n=0 then 1 %p A135224 elif k=0 then 2^n +1 %p A135224 else add(binomial(n, k+j), j=0..n) %p A135224 fi; end: %p A135224 seq(seq(T(n, k), k=0..n), n=0..10); # _G. C. Greubel_, Nov 20 2019 %t A135224 T[n_, k_]:= T[n, k] = If[k==n==0, 1, If[k==0, 2^n +1, Sum[Binomial[n, k + j], {j, 0, n}]]]; Table[T[n, k], {n, 0, 10}, {k, 0, n}]//Flatten (* _G. C. Greubel_, Nov 20 2019 *) %o A135224 (PARI) T(n,k) = if(k==0 && n==0, 1, if(k==0, 2^n +1, sum(j=0, n, binomial(n, k+j)) )); \\ _G. C. Greubel_, Nov 20 2019 %o A135224 (Magma) %o A135224 function T(n,k) %o A135224 if k eq 0 and n eq 0 then return 1; %o A135224 elif k eq 0 then return 2^n +1; %o A135224 else return (&+[Binomial(n, k+j): j in [0..n]]); %o A135224 end if; return T; end function; %o A135224 [T(n,k): k in [0..n], n in [0..10]]; // _G. C. Greubel_, Nov 20 2019 %o A135224 (Sage) %o A135224 def T(n, k): %o A135224 if (k==0 and n==0): return 1 %o A135224 elif (k==0): return 2^n + 1 %o A135224 else: return sum(binomial(n, k+j) for j in (0..n)) %o A135224 [[T(n, k) for k in (0..n)] for n in (0..10)] # _G. C. Greubel_, Nov 20 2019 %Y A135224 Cf. A083318, A103451, A132750. %K A135224 nonn,tabl %O A135224 0,2 %A A135224 _Gary W. Adamson_, Nov 23 2007