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 A083861 #44 Sep 08 2022 08:45:10 %S A083861 0,0,1,0,1,5,0,1,5,19,0,1,5,20,65,0,1,5,21,75,211,0,1,5,22,85,275,665, %T A083861 0,1,5,23,95,341,1000,2059,0,1,5,24,105,409,1365,3625,6305,0,1,5,25, %U A083861 115,479,1760,5461,13125,19171,0,1,5,26,125,551,2185,7573,21845,47500,58025 %N A083861 Square array T(n,k) of second binomial transforms of generalized Fibonacci numbers, read by ascending antidiagonals, with n, k >= 0. %C A083861 Row n >= 0 of the array gives the solution to the recurrence b(k) = 5*b(k-1) + (n - 6)*b(k-2) for k >= 2 with b(0) = 0 and b(1) = 1. The rows are the binomial transforms of the rows of array A083857. The rows are the second binomial transforms of the generalized Fibonacci numbers in array A083856. %H A083861 G. C. Greubel, <a href="/A083861/b083861.txt">Antidiagonals n = 0..100, flattened</a> %H A083861 OEIS, <a href="https://oeis.org/transforms.html">Transformations of integer sequences</a>. %F A083861 T(n, k) = (((5 + sqrt(4*n + 1))/2)^k - ((5 - sqrt(4*n + 1))/2)^k)/sqrt(4*n + 1). %F A083861 O.g.f. for row n >= 0: -x/(-1 + 5*x + (n-6)*x^2) . - _R. J. Mathar_, Dec 02 2007 %F A083861 From _Petros Hadjicostas_, Dec 25 2019: (Start) %F A083861 T(n,k) = 5*T(n,k-1) + (n - 6)*T(n,k-2) for k >= 2 with T(n,0) = 0 and T(n,1) = 1 for all n >= 0. %F A083861 T(n,k) = Sum_{i = 0..k} binomial(k,i) * A083857(n,i). %F A083861 T(n,k) = Sum_{i = 0..k} Sum_{j = 0..i} binomial(k,i) * binomial(i,j) * A083856(n,j). (End) %e A083861 Array T(n,k) (with rows n >= 0 and columns k >= 0) begins as follows: %e A083861 0, 1, 5, 19, 65, 211, 665, 2059, 6305, 19171, ... %e A083861 0, 1, 5, 20, 75, 275, 1000, 3625, 13125, 47500, ... %e A083861 0, 1, 5, 21, 85, 341, 1365, 5461, 21845, 87381, ... %e A083861 0, 1, 5, 22, 95, 409, 1760, 7573, 32585, 140206, ... %e A083861 0, 1, 5, 23, 105, 479, 2185, 9967, 45465, 207391, ... %e A083861 0, 1, 5, 24, 115, 551, 2640, 12649, 60605, 290376, ... %e A083861 0, 1, 5, 25, 125, 625, 3125, 15625, 78125, 390625, ... %e A083861 ... %p A083861 seq(seq(round( (((5+sqrt(4*(n-k)+1))/2)^k - ((5-sqrt(4*(n-k)+1))/2)^k)/sqrt(4*(n-k)+1) ), k=0..n), n=0..10); # _G. C. Greubel_, Dec 27 2019 %t A083861 T[n_, k_]:= Round[(((5 +Sqrt[4*n+1])/2)^k - ((5 -Sqrt[4*n+1])/2)^k)/Sqrt[4*n+1]]; Table[T[n-k, k], {n, 0, 10}, {k, 0, n}]//Flatten (* _G. C. Greubel_, Dec 27 2019 *) %o A083861 (PARI) T(n, k) = round( (((5+sqrt(4*n+1))/2)^k - ((5-sqrt(4*n+1))/2)^k)/sqrt(4*n + 1) ); %o A083861 for(n=0,10, for(k=0,n, print1(T(n-k,k), ", "))) \\ _G. C. Greubel_, Dec 27 2019 %o A083861 (Magma) %o A083861 T:= func< n,k | Round( (((5+Sqrt(4*n+1))/2)^k - ((5-Sqrt(4*n+1))/2)^k)/Sqrt(4*n + 1) ) >; %o A083861 [T(n-k,k): k in [0..n], n in [0..10]]; // _G. C. Greubel_, Dec 27 2019 %o A083861 (Sage) [[round( (((5+sqrt(4*(n-k)+1))/2)^k - ((5-sqrt(4*(n-k)+1))/2)^k)/sqrt(4*(n-k)+1) ) for k in (0..n)] for n in (0..10)] # _G. C. Greubel_, Dec 27 2019 %Y A083861 Rows include A001047 (n=0), A093131 (n=1), A002450 (n=2), A004254 (n=5), A000351 (n=6), A052918 (n=7), A015535 (n=8), A015536 (n=9), A015537 (n=10). %Y A083861 Cf. A083856 (second inverse binomial transform), A083856 (first inverse binomial transform), A082297 (main diagonal). %K A083861 easy,nonn,tabl %O A083861 0,6 %A A083861 _Paul Barry_, May 06 2003 %E A083861 Name and various sections edited by _Petros Hadjicostas_, Dec 25 2019