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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A067425 Triangle with columns built from certain power sequences.

Original entry on oeis.org

1, 4, 1, 16, 5, 1, 64, 40, 6, 1, 256, 320, 72, 7, 1, 1024, 2560, 864, 112, 8, 1, 4096, 20480, 10368, 1792, 160, 9, 1, 16384, 163840, 124416, 28672, 3200, 216, 10, 1, 65536, 1310720, 1492992, 458752, 64000
Offset: 0

Views

Author

Wolfdieter Lang, Jan 25 2002

Keywords

Comments

The fifth column (m=4) gives [1, 8, 160, 3200, 64000, 1280000, 25600000, ...].

Examples

			Triangle starts:
   1;
   4,  1;
  16,  5,  1;
  64, 40,  6,  1;
  ...
		

Crossrefs

Columns 0..3 are A000302 (powers of 4), A067412, A067419, A067404.
Columns 5..8 are A067426, A067427, A067428, A067429.

Programs

  • Mathematica
    A067425[n_, m_] := If[n == m, 1, (m + 4)*(4*(m + 1))^(n - m - 1)];
    Table[A067425[n, m], {n, 0, 10}, {m, 0, n}] (* Paolo Xausa, Oct 16 2024 *)

Formula

T(n,m) = 1 if n = m; T(n,m) = (m+4)*(4*(m+1))^(n-m-1) if n > m >= 0, else 0.
G.f. for column m: (x^m)*(1-3*m*x)/(1-4*(m+1)*x).

A067428 Eighth column of triangle A067425.

Original entry on oeis.org

1, 11, 352, 11264, 360448, 11534336, 369098752, 11811160064, 377957122048, 12094627905536, 387028092977152, 12384898975268864, 396316767208603648, 12682136550675316736, 405828369621610135552, 12986507827891524337664
Offset: 0

Views

Author

Wolfdieter Lang, Jan 25 2002

Keywords

Crossrefs

Cf. A067427 (seventh column), A067429 (ninth column), A009976 (powers of 32).

Programs

  • Magma
    [Ceiling(11*(4*8)^(n-1)): n in [0..20]]; // Vincenzo Librandi, Oct 03 2011
  • Mathematica
    LinearRecurrence[{32}, {1, 11}, 20] (* Paolo Xausa, Oct 16 2024 *)

Formula

a(n) = A067425(n+7, 7).
a(n) = 11*(4*8)^(n-1), n > =1, a(0)=1.
G.f.: (1-21*x)/(1-32*x).
Showing 1-2 of 2 results.