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.

Showing 1-2 of 2 results.

A263575 Stirling transform of Lucas numbers (A000032).

Original entry on oeis.org

2, 1, 4, 14, 53, 227, 1092, 5791, 33350, 206511, 1365563, 9590847, 71216713, 556861216, 4569168866, 39222394456, 351304769679, 3275433717440, 31723522878974, 318571978752719, 3311400814816987, 35573458376435132, 394404160256111139, 4507130777468928696
Offset: 0

Views

Author

Vladimir Reshetnikov, Oct 21 2015

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Sum[LucasL[k] StirlingS2[n, k], {k, 0, n}], {n, 0, 23}]
    Table[Simplify[BellB[n, GoldenRatio] + BellB[n, 1 - GoldenRatio]], {n, 0, 23}]

Formula

a(n) = Sum_{k=0..n} A000032(k)*Stirling2(n,k).
Let phi = (1+sqrt(5))/2.
a(n) = B_n(phi)+B_n(1-phi), where B_n(x) is n-th Bell polynomial.
2*B_n(phi) = a(n) + A263576*sqrt(5).
E.g.f.: exp((exp(x)-1)*phi)+exp((exp(x)-1)*(1-phi)).
Sum_{k=0..n} a(k)*Stirling1(n,k) = A000032(n).
G.f.: Sum_{j>=0} Lucas(j)*x^j / Product_{k=1..j} (1 - k*x). - Ilya Gutkovskiy, Apr 06 2019

A323620 Expansion of e.g.f. 2*sqrt(1 + x)*sinh(sqrt(5)*log(1 + x)/2)/sqrt(5).

Original entry on oeis.org

0, 1, 0, 1, -4, 19, -108, 719, -5496, 47465, -457160, 4858865, -56490060, 713165035, -9715762980, 142069257055, -2219386098160, 36889108220305, -650018185589520, 12103669982341025, -237476572759473300, 4896758300881695875, -105866710959427454300, 2394660132226522508975
Offset: 0

Views

Author

Ilya Gutkovskiy, Jan 20 2019

Keywords

Crossrefs

Programs

  • Magma
    [(&+[StirlingFirst(n,k)*Fibonacci(k): k in [0..n]]): n in [0..25]]; // G. C. Greubel, Feb 07 2019
    
  • Mathematica
    FullSimplify[nmax = 23; CoefficientList[Series[2 Sqrt[1 + x] Sinh[Sqrt[5] Log[1 + x]/2]/Sqrt[5], {x, 0, nmax}], x] Range[0, nmax]!]
    Table[Sum[StirlingS1[n, k] Fibonacci[k], {k, 0, n}], {n, 0, 23}]
  • PARI
    {a(n) = sum(k=0,n, stirling(n,k,1)*fibonacci(k))};
    vector(25, n, n--; a(n)) \\ G. C. Greubel, Feb 07 2019
    
  • Sage
    [sum((-1)^(k+n)*stirling_number1(n,k)*fibonacci(k) for k in (0..n)) for n in (0..25)] # G. C. Greubel, Feb 07 2019

Formula

a(n) = Sum_{k=0..n} Stirling1(n,k)*A000045(k).
From Vaclav Kotesovec, Jan 21 2019: (Start)
a(n) = -(-1)^n * cos(sqrt(5)*Pi/2) * (Gamma((3 + sqrt(5))/2) * Gamma(n - (1 + sqrt(5))/2) - Gamma((3 - sqrt(5))/2) * Gamma(n + (sqrt(5) - 1)/2)) / (Pi*sqrt(5)).
a(n) ~ -(-1)^n * n! / (sqrt(5) * Gamma((sqrt(5)-1)/2) * n^((3 - sqrt(5))/2)).
a(n) = -2*(n-2)*a(n-1) - (n^2 - 5*n + 5)*a(n-2). (End)
Showing 1-2 of 2 results.