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.

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A172345 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=7.

Original entry on oeis.org

1, 1, 1, 1, 7, 1, 1, 50, 50, 1, 1, 357, 2550, 357, 1, 1, 2549, 129999, 129999, 2549, 1, 1, 18200, 6627400, 47319636, 6627400, 18200, 1, 1, 129949, 337867400, 17224480052, 17224480052, 337867400, 129949, 1, 1, 927843, 17224610001, 6269758040364
Offset: 0

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Author

Roger L. Bagula, Feb 01 2010

Keywords

Comments

Start from the generalized Fibonacci sequence A054413 and its partial products c(n) = 1, 1, 7, 350, 124950, 318497550, 5796655410000,... Then t(n,k) = c(n)/(c(k)*c(n-k)).
Row sums are 1, 2, 9, 102, 3266, 265098, 60610838, 35124954804, 57340390811566,
237262009585104396, 2765506241462282647452,...}

Examples

			1;
1, 1;
1, 7, 1;
1, 50, 50, 1;
1, 357, 2550, 357, 1;
1, 2549, 129999, 129999, 2549, 1;
1, 18200, 6627400, 47319636, 6627400, 18200, 1;
1, 129949, 337867400, 17224480052, 17224480052, 337867400, 129949, 1;
1, 927843, 17224610001, 6269758040364, 44766423655148, 6269758040364, 17224610001, 927843, 1;
		

Crossrefs

Cf. A010048 (m=1), A099927 (m=2), A172343 (m=6), A172346 (m=8).

Programs

  • Mathematica
    Clear[f, c, a, t];
    f[0, a_] := 0; f[1, a_] := 1;
    f[n_, a_] := f[n, a] = a*f[n - 1, 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}]

A172339 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=3.

Original entry on oeis.org

1, 1, 1, 1, 3, 1, 1, 10, 10, 1, 1, 33, 110, 33, 1, 1, 109, 1199, 1199, 109, 1, 1, 360, 13080, 43164, 13080, 360, 1, 1, 1189, 142680, 1555212, 1555212, 142680, 1189, 1, 1, 3927, 1556401, 56030436, 185070228, 56030436, 1556401, 3927, 1, 1, 12970, 16977730
Offset: 0

Views

Author

Roger L. Bagula, Feb 01 2010

Keywords

Comments

Build with the recipe of A010048 (m=1) and A099927 (m=2).
Start from the generalized Fibonacci sequence A006190 and its partial products c(n) = 1, 1, 3, 30, 990, 107910, 38847600, 46189796400,... Then t(n,k) = c(n)/(c(k)*c(n-k)).
Row sums are 1, 2, 5, 22, 178, 2618, 70046, 3398164, 300251758, 48114604076,
14041125439724,...

Examples

			1;
1, 1;
1, 3, 1;
1, 10, 10, 1;
1, 33, 110, 33, 1;
1, 109, 1199, 1199, 109, 1;
1, 360, 13080, 43164, 13080, 360, 1;
1, 1189, 142680, 1555212, 1555212, 142680, 1189, 1;
1, 3927, 1556401, 56030436, 185070228, 56030436, 1556401, 3927, 1;
1, 12970, 16977730, 2018652097, 22021659240, 22021659240, 2018652097, 16977730, 12970, 1;
		

Crossrefs

Cf. A010048 (m=1), A099927 (m=2), A034802 (m=4), A172342 (m=5).

Programs

  • Mathematica
    Clear[f, c, a, t];
    f[0, a_] := 0; f[1, a_] := 1;
    f[n_, a_] := f[n, a] = a*f[n - 1, 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}]

A172346 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=8.

Original entry on oeis.org

1, 1, 1, 1, 8, 1, 1, 65, 65, 1, 1, 528, 4290, 528, 1, 1, 4289, 283074, 283074, 4289, 1, 1, 34840, 18678595, 151727664, 18678595, 34840, 1, 1, 283009, 1232504195, 81326315267, 81326315267, 1232504195, 283009, 1, 1, 2298912, 81326598276
Offset: 0

Views

Author

Roger L. Bagula, Feb 01 2010

Keywords

Comments

Start from the generalized Fibonacci sequence A041025 and its partial products c(n) = 1, 1, 8, 520, 274560, 1177587840, 41027160345600,... Then t(n,k) = c(n)/(c(k)*c(n-k)).
Row sums are 1, 2, 10, 132, 5348, 574728, 189154536, 165118204944, 441439547818768, 3130197658239760416, 67978275921898969849504,...

Examples

			1;
1, 1;
1, 8, 1;
1, 65, 65, 1;
1, 528, 4290, 528, 1;
1, 4289, 283074, 283074, 4289, 1;
1, 34840, 18678595, 151727664, 18678595, 34840, 1;
1, 283009, 1232504195, 81326315267, 81326315267, 1232504195, 283009, 1;
1, 2298912, 81326598276, 43591056675936, 354094776672518, 43591056675936, 81326598276, 2298912, 1;
		

Crossrefs

Cf. A010048 (m=1), A099927 (m=2), A172345 (m=7).

Programs

  • Mathematica
    Clear[f, c, a, t];
    f[0, a_] := 0; f[1, a_] := 1;
    f[n_, a_] := f[n, a] = a*f[n - 1, 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}]

A383719 a(n) = Pell(n) * Pell(n-1) * Pell(n-2) * Pell(n-3) * Pell(n-4) / 3480.

Original entry on oeis.org

1, 70, 5915, 482664, 39618670, 3248730940, 266442347522, 21851425660680, 1792084691254935, 146972777186757522, 12053560080255418725, 988538895611708641200, 81072243052956528402380, 6648912468496274313591800, 545291894670184984544154100, 44720584275276797753993516592
Offset: 5

Views

Author

Seiichi Manyama, May 07 2025

Keywords

Crossrefs

Fifth column of triangle A099927.
Cf. A000129.

Programs

  • PARI
    pell(n) = ([2, 1; 1, 0]^n)[2, 1];
    p(n, k) = prod(j=0, k-1, pell(n-j));
    a(n) = p(n, 5)/p(5, 5);
    
  • Sage
    def a(n): return ((1+sqrt(2))^(5*(n-5))*q_binomial(n, 5, -(3-2*sqrt(2)))).simplify_full()

Formula

G.f.: x^5 * exp( Sum_{k>=1} Pell(6*k)/Pell(k) * x^k/k ).
G.f.: x^5 / ((1-2*x-x^2) * (1+14*x-x^2) * (1-82*x-x^2)).
a(n) = 70*a(n-1) + 1015*a(n-2) - 2436*a(n-3) - 1015*a(n-4) + 70*a(n-5) + a(n-6).
a(n) = (1 + sqrt(2))^(5*(n-5)) * q-binomial(n, 5, -(sqrt(2) - 1)^2).
Previous Showing 11-14 of 14 results.