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 A081572 #19 Sep 08 2022 08:45:09 %S A081572 1,1,1,1,2,2,1,3,5,3,1,4,10,13,5,1,5,17,35,34,8,1,6,26,75,125,89,13,1, %T A081572 7,37,139,338,450,233,21,1,8,50,233,757,1541,1625,610,34,1,9,65,363, %U A081572 1490,4172,7069,5875,1597,55,1,10,82,535,2669,9633,23165,32532,21250,4181,89 %N A081572 Square array of binomial transforms of Fibonacci numbers, read by ascending antidiagonals. %C A081572 Array rows are solutions of the recurrence a(n) = (2*k+1)*a(n-1) - A028387(k-1)*a(n-2), where a(0) = 1 and a(1) = k+1. %H A081572 G. C. Greubel, <a href="/A081572/b081572.txt">Antidiagonal rows n = 0..50, flattened</a> %F A081572 Rows are successive binomial transforms of F(n+1). %F A081572 T(n, k) = ((5+sqrt(5))/10)*( (2*n + 1 + sqrt(5))/2)^k + ((5-sqrt(5)/10)*( 2*n + 1 - sqrt(5))/2 )^k. %F A081572 From _G. C. Greubel_, May 27 2021: (Start) %F A081572 T(n, k) = Sum_{j=0..k} binomial(k,j)*n^(k-j)*Fibonacci(j+1) (square array). %F A081572 T(n, k) = Sum_{j=0..k} binomial(k,j)*(n-k)^(k-j)*Fibonacci(j+1) (antidiagonal triangle). (End) %e A081572 The array rows begins as: %e A081572 1, 1, 2, 3, 5, 8, 13, ... A000045; %e A081572 1, 2, 5, 13, 34, 89, 233, ... A001519; %e A081572 1, 3, 10, 35, 125, 450, 1625, ... A081567; %e A081572 1, 4, 17, 75, 338, 1541, 7069, ... A081568; %e A081572 1, 5, 26, 139, 757, 4172, 23165, ... A081569; %e A081572 1, 6, 37, 233, 1490, 9633, 62753, ... A081570; %e A081572 1, 7, 50, 363, 2669, 19814, 148153, ... A081571; %e A081572 Antidiagonal triangle begins as: %e A081572 1; %e A081572 1, 1; %e A081572 1, 2, 2; %e A081572 1, 3, 5, 3; %e A081572 1, 4, 10, 13, 5; %e A081572 1, 5, 17, 35, 34, 8; %e A081572 1, 6, 26, 75, 125, 89, 13; %e A081572 1, 7, 37, 139, 338, 450, 233, 21; %e A081572 1, 8, 50, 233, 757, 1541, 1625, 610, 34; %t A081572 T[n_, k_]:= If[n==0, Fibonacci[k+1], Sum[Binomial[k, j]*Fibonacci[j+1]*n^(k-j), {j, 0, k}]]; Table[T[n-k, k], {n,0,12}, {k,0,n}]//Flatten (* _G. C. Greubel_, May 26 2021 *) %o A081572 (Magma) %o A081572 A081572:= func< n,k | (&+[Binomial(k,j)*Fibonacci(j+1)*(n-k)^(k-j): j in [0..k]]) >; %o A081572 [A081572(n,k): k in [0..n], n in [0..12]]; // _G. C. Greubel_, May 27 2021 %o A081572 (Sage) %o A081572 def A081572(n,k): return sum( binomial(k,j)*fibonacci(j+1)*(n-k)^(k-j) for j in (0..k) ) %o A081572 flatten([[A081572(n,k) for k in (0..n)] for n in (0..12)]) # _G. C. Greubel_, May 27 2021 %Y A081572 Array row n: A000045 (n=0), A001519 (n=1), A081567 (n=2), A081568 (n=3), A081569 (n=4), A081570 (n=5), A081571 (n=6). %Y A081572 Array column k: A000027 (k=1), A002522 (k=2). %Y A081572 Different from A073133. %Y A081572 Cf. A028387. %K A081572 easy,nonn,tabl %O A081572 0,5 %A A081572 _Paul Barry_, Mar 22 2003