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.

A367300 Triangular array T(n,k), read by rows: coefficients of strong divisibility sequence of polynomials p(1,x) = 1, p(2,x) = 3 + 2*x, p(n,x) = u*p(n-1,x) + v*p(n-2,x) for n >= 3, where u = p(2,x), v = 1 - 2*x - x^2.

Original entry on oeis.org

1, 3, 2, 10, 10, 3, 33, 46, 22, 4, 109, 194, 131, 40, 5, 360, 780, 678, 296, 65, 6, 1189, 3036, 3228, 1828, 581, 98, 7, 3927, 11546, 14514, 10100, 4194, 1036, 140, 8, 12970, 43150, 62601, 51664, 26479, 8604, 1722, 192, 9, 42837, 159082, 261598, 249720, 152245, 61318, 16248, 2712, 255, 10
Offset: 1

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Author

Clark Kimberling, Dec 23 2023

Keywords

Comments

Because (p(n,x)) is a strong divisibility sequence, for each integer k, the sequence (p(n,k)) is a strong divisibility sequence of integers.

Examples

			First eight rows:
     1
     3      2
    10     10      3
    33     46     22      4
   109    194    131     40     5
   360    780    678    296    65     6
  1189   3036   3228   1828   581    98    7
  3927  11546  14514  10100  4194  1036  140  8
Row 4 represents the polynomial p(4,x) = 33 + 46*x + 22*x^2 + 4*x^3, so (T(4,k)) = (33,46,22,4), k=0..3.
		

Crossrefs

Cf. A006190 (column 1); A000027 (p(n,n-1)); A107839 (row sums, p(n,1)); A001045 (alternating row sums, p(n,-1)); A030240 (p(n,2)); A039834 (signed Fibonacci numbers, p(n,-2)); A016130 (p(n,3)); A225883 (p(n,-3)); A099450 (p(n,-4)); A094440, A367208, A367209, A367210, A367211, A367297, A367298, A367299.

Programs

  • Mathematica
    p[1, x_] := 1; p[2, x_] := 3 + 2 x; u[x_] := p[2, x]; v[x_] := 1 - 2 x - x^2;
    p[n_, x_] := Expand[u[x]*p[n - 1, x] + v[x]*p[n - 2, x]]
    Grid[Table[CoefficientList[p[n, x], x], {n, 1, 10}]]
    Flatten[Table[CoefficientList[p[n, x], x], {n, 1, 10}]]

Formula

p(n,x) = u*p(n-1,x) + v*p(n-2,x) for n >= 3, where p(1,x) = 1, p(2,x) = 3 + 2*x, u = p(2,x), and v = 1 - 2*x - x^2.
p(n,x) = k*(b^n - c^n), where k = -(1/sqrt(13 + 4*x)), b = (1/2) (2*x + 3 + 1/k), c = (1/2) (2*x + 3 - 1/k).