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.

A172349 Triangle t(n,k) read by rows: fibonomial ratios c(n)/(c(k)*c(n-k)) where c are partial products of a generalized Fibonacci sequence with multiplier m=4.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 5, 5, 1, 1, 9, 45, 9, 1, 1, 29, 261, 261, 29, 1, 1, 65, 1885, 3393, 1885, 65, 1, 1, 181, 11765, 68237, 68237, 11765, 181, 1, 1, 441, 79821, 1037673, 3343613, 1037673, 79821, 441, 1, 1, 1165, 513765, 18598293, 134321005, 134321005
Offset: 0

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Author

Roger L. Bagula and Gary W. Adamson, Feb 01 2010

Keywords

Comments

Start from the generalized Fibonacci sequence A006131 and its partial products c(n) = 1, 1, 1, 5, 45, 1305, 84825, 15353325, 6770816325, 7888001018625... Then t(n,k) = c(n)/(c(k)*c(n-k)).
Row sums are 1, 2, 3, 12, 65, 582, 7295, 160368, 5579485, 306868458, 26280601275,...

Examples

			1;
1, 1;
1, 1, 1;
1, 5, 5, 1;
1, 9, 45, 9, 1;
1, 29, 261, 261, 29, 1;
1, 65, 1885, 3393, 1885, 65, 1;
1, 181, 11765, 68237, 68237, 11765, 181, 1;
1, 441, 79821, 1037673, 3343613, 1037673, 79821, 441, 1;
1, 1165, 513765, 18598293, 134321005, 134321005, 18598293, 513765, 1165, 1;
1, 2929, 3412285, 300963537, 6052711133, 13566421505, 6052711133, 300963537, 3412285, 2929, 1;
		

Crossrefs

Cf. A010048 (m=1), A015109 (m=2), A172347 (m=3), A172350 (m=5).

Programs

  • Mathematica
    Clear[f, c, a, t];
    f[0, a_] := 0; f[1, a_] := 1;
    f[n_, a_] := f[n, a] = f[n - 1, a] + a*f[n - 2, a];
    c[n_, a_] := If[n == 0, 1, Product[f[i, a], {i, 1, n}]];
    t[n_, m_, a_] := c[n, a]/(c[m, a]*c[n - m, a]);
    Table[Table[Table[t[n, m, a], {m, 0, n}], {n, 0, 10}], {a, 1, 10}];
    Table[Flatten[Table[Table[t[n, m, a], {m, 0, n}], {n, 0, 10}]], {a, 1, 10}]