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.

A139700 Binomial transform of [1, 30, 30, 30, ...].

Original entry on oeis.org

1, 31, 91, 211, 451, 931, 1891, 3811, 7651, 15331, 30691, 61411, 122851, 245731, 491491, 983011, 1966051, 3932131, 7864291, 15728611, 31457251, 62914531, 125829091, 251658211, 503316451, 1006632931, 2013265891, 4026531811, 8053063651, 16106127331
Offset: 1

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Author

Gary W. Adamson, Apr 29 2008

Keywords

Comments

The binomial transform of [1, c, c, c, ...] has the terms a(n) = 1 - c + c*2^(n-1) if the offset 1 is chosen. The o.g.f. of the a(n) is x{1+(c-2)x}/{(2x-1)(x-1)}. This applies to A139634 with c=10, to A139635 with c=11, to A139697 with c=12, to A139698 with c=25 and to A099003, A139700, A139701 accordingly. - R. J. Mathar, May 11 2008

Examples

			a(3) = 91 = (1, 2, 1) dot (1, 30, 30) = (1 + 60 + 30).
		

Crossrefs

Programs

  • Maple
    seq(30*2^(n-1)-29,n=1..27); # Emeric Deutsch, May 07 2008
  • Mathematica
    LinearRecurrence[{3,-2},{1,31},30] (* Harvey P. Dale, Apr 18 2018 *)
  • PARI
    Vec(x*(28*x+1)/((x-1)*(2*x-1)) + O(x^100)) \\ Colin Barker, Mar 11 2014

Formula

A007318 * [1, 30, 30, 30, ...].
a(n) = 30*2^(n-1) - 29. - Emeric Deutsch, May 07 2008
a(n) = 2*a(n-1) + 29 (with a(1)=1). - Vincenzo Librandi, Nov 24 2010
From Colin Barker, Mar 11 2014: (Start)
a(n) = 3*a(n-1) - 2*a(n-2).
G.f.: x*(28*x+1) / ((x-1)*(2*x-1)). (End)

Extensions

More terms from Emeric Deutsch, May 07 2008
More terms from Colin Barker, Mar 11 2014