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.

A213575 Antidiagonal sums of the convolution array A213573.

Original entry on oeis.org

1, 10, 47, 158, 441, 1098, 2539, 5590, 11909, 24818, 50967, 103662, 209521, 421786, 846947, 1697990, 3400893, 6807618, 13622095, 27252190, 54513641, 109037930, 218088027, 436189878, 872395381, 1744808338, 3489636359
Offset: 1

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Author

Clark Kimberling, Jun 18 2012

Keywords

Crossrefs

Programs

  • GAP
    List([1..30], n-> 13*2^(n+1)-(n^3+6*n^2+18*n+26)); # G. C. Greubel, Jul 25 2019
  • Magma
    [13*2^(n+1)-(n^3+6*n^2+18*n+26): n in [1..30]]; // G. C. Greubel, Jul 25 2019
    
  • Mathematica
    (* First program *)
    b[n_]:= 2^(n-1); c[n_]:= n^2;
    t[n_, k_]:= Sum[b[k-i] c[n+i], {i, 0, k-1}]
    TableForm[Table[t[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[t[n-k+1, k], {n, 12}, {k, n, 1, -1}]]
    r[n_]:= Table[t[n, k], {k, 1, 60}]  (* A213573 *)
    d = Table[t[n, n], {n, 1, 40}] (* A213574 *)
    s[n_]:= Sum[t[i, n+1-i], {i, 1, n}]
    s1 = Table[s[n], {n, 1, 50}] (* A213575 *)
    (* Additional programs *)
    Table[Sum[k^3*2^(n-k),{k,0,n}],{n,1,30}] (* Vaclav Kotesovec, Nov 28 2013 *)
  • PARI
    vector(30, n, 13*2^(n+1)-(n^3+6*n^2+18*n+26)) \\ G. C. Greubel, Jul 25 2019
    
  • Sage
    [13*2^(n+1)-(n^3+6*n^2+18*n+26) for n in (1..30)] # G. C. Greubel, Jul 25 2019
    

Formula

a(n) = 6*a(n-1) - 14*a(n-2) + 16*a(n-3) - 9*a(n-4) + 2*a(n-5).
G.f.: x*(1 + 4 x + x^2)/((1 - 2*x)*(1 - x)^4).
From Stanislav Sykora, Nov 27 2013: (Start)
a(n) = 2^n*Sum_{k=0..n} k^p*q^k, for p=3, q=1/2.
a(n) = 2^(n+1)*13 - (n^3 + 6*n^2 + 18*n + 26). (End)
a(n) = 2*a(n-1) + n^3. - Sochima Everton, Biereagu, Jul 14 2019
E.g.f.: 26*exp(2*x) - (26 +25*x +9*x^2 +x^3)*exp(x). - G. C. Greubel, Jul 25 2019