cp's OEIS Frontend

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.

A081572 Square array of binomial transforms of Fibonacci numbers, read by ascending antidiagonals.

This page as a plain text file.
%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