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 A213774 #21 Jul 10 2019 09:06:25 %S A213774 1,5,3,14,11,5,31,26,17,7,61,53,38,23,9,112,99,75,50,29,11,197,176, %T A213774 137,97,62,35,13,337,303,240,175,119,74,41,15,566,511,409,304,213,141, %U A213774 86,47,17,939,850,685,515,368,251,163,98,53,19,1545,1401,1134 %N A213774 Rectangular array: (row n) = b**c, where b(h) = F(h+1), c(h) = 2*n-3+2*h, F=A000045 (Fibonacci numbers), n>=1, h>=1, and ** = convolution. %C A213774 Principal diagonal: A213775. %C A213774 Antidiagonal sums: A213776. %C A213774 Row 1, (1,2,3,5,8,...)**(1,3,5,7,9,...): A023652. %C A213774 Row 2, (1,2,3,5,8,...)**(3,5,7,9,11,...). %C A213774 Row 3, (1,2,3,5,8,...)**(5,7,9,11,13,...). %C A213774 For a guide to related arrays, see A213500. %H A213774 Clark Kimberling, <a href="/A213774/b213774.txt">Antidiagonals n=1..60, flattened</a> %F A213774 T(n,k) = 3*T(n,k-1)-2*T(n,k-2)-T(n,k-3)+T(n,k-4). %F A213774 G.f. for row n: f(x)/g(x), where f(x) = x*(2*n - 1 + 2*x - (2*n - 3)*x^2) and g(x) = (1 - x - x^2)*(1 - x )^2. %F A213774 T(n,k) = 2*n*Fibonacci(k+3) + Lucas(k+3) - 4*(k+n+1). - _Ehren Metcalfe_, Jul 08 2019 %e A213774 Northwest corner (the array is read by falling antidiagonals): %e A213774 1....5....14...31....61....112 %e A213774 3....11...26...53....99....176 %e A213774 5....17...38...75....137...240 %e A213774 7....23...50...97....175...304 %e A213774 9....29...62...119...213...368 %e A213774 11...35...74...141...251...432 %t A213774 b[n_] := Fibonacci[n + 1]; c[n_] := 2 n - 1; %t A213774 t[n_, k_] := Sum[b[k - i] c[n + i], {i, 0, k - 1}] %t A213774 TableForm[Table[t[n, k], {n, 1, 10}, {k, 1, 10}]] %t A213774 Flatten[Table[t[n - k + 1, k], {n, 12}, {k, n, 1, -1}]] %t A213774 r[n_] := Table[t[n, k], {k, 1, 60}] (* A213774 *) %t A213774 Table[t[n, n], {n, 1, 40}] (* A213775 *) %t A213774 s[n_] := Sum[t[i, n + 1 - i], {i, 1, n}] %t A213774 Table[s[n], {n, 1, 50}] (* A213776 *) %Y A213774 Cf. A023652, A213500, A213768, A213775, A213776. %K A213774 nonn,tabl,easy %O A213774 1,2 %A A213774 _Clark Kimberling_, Jun 21 2012