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.

A144297 BINOMIAL transform of A001515.

Original entry on oeis.org

1, 3, 12, 65, 465, 4212, 46441, 604389, 9071250, 154267865, 2931801639, 61578273462, 1416474723373, 35415138314415, 956276678789100, 27733572777976973, 859779201497486829, 28373745267763162716, 993110842735800666085, 36746019445535955976665
Offset: 0

Views

Author

N. J. A. Sloane, Dec 04 2008

Keywords

Crossrefs

Cf. A001515.

Programs

  • Magma
    I:=[1,3,12]; [n le 3 select I[n] else (2*n-1)*Self(n-1) -(4*n-9)*Self(n-2) +2*(n-3)*Self(n-3): n in [1..30]]; // G. C. Greubel, Sep 28 2023
    
  • Mathematica
    CoefficientList[Series[E^(1+x-Sqrt[1-2*x])/Sqrt[1-2*x],{x,0,20}],x]*Range[0, 20]! (* Vaclav Kotesovec, Oct 20 2012 *)
  • SageMath
    def A144297_list(prec):
        P. = PowerSeriesRing(QQ, prec)
        return P( exp(1+x-sqrt(1-2*x))/sqrt(1-2*x) ).egf_to_ogf().list()
    A144297_list(40) # G. C. Greubel, Sep 28 2023

Formula

From Vaclav Kotesovec, Oct 20 2012: (Start)
E.g.f.: exp(1+x-sqrt(1-2*x))/sqrt(1-2*x).
Recurrence: a(n) = (2*n+1)*a(n-1) - (4*n-5)*a(n-2) + 2*(n-2)*a(n-3).
a(n) ~ 2^(n+1/2)*n^n/exp(n-3/2). (End)
a(n) = Sum_{j=0..n} binomial(n,j)*A001515(j). - G. C. Greubel, Sep 28 2023