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.

A382514 Expansion of 1/(1 - x/(1 - 4*x)^(3/2)).

Original entry on oeis.org

1, 1, 7, 43, 255, 1493, 8695, 50517, 293163, 1700335, 9859019, 57156631, 331332423, 1920621431, 11132911939, 64531189379, 374047777319, 2168115796941, 12567146992975, 72843402779669, 422224417571347, 2447350774345341, 14185640454054279, 82224565359415849
Offset: 0

Views

Author

Seiichi Manyama, Mar 30 2025

Keywords

Crossrefs

Programs

  • Magma
    R := PowerSeriesRing(Rationals(), 40); f := 1/(1 - x/(1 - 4*x)^(3/2)); seq := [ Coefficient(f, n) : n in [0..30] ]; seq; // Vincenzo Librandi, Apr 09 2025
  • Mathematica
    Table[Sum[4^(n-k)*Binomial[n+k/2-1,n-k],{k,0,n}],{n,0,35}] (* Vincenzo Librandi, Apr 09 2025 *)
  • PARI
    a(n) = sum(k=0, n, 4^(n-k)*binomial(n+k/2-1, n-k));
    

Formula

a(n) = Sum_{k=0..n} 4^(n-k) * binomial(n+k/2-1,n-k).
D-finite with recurrence (-n+1)*a(n) +2*(8*n-13)*a(n-1) +5*(-19*n+43)*a(n-2) +2*(126*n-361)*a(n-3) +128*(-2*n+7)*a(n-4)=0. - R. J. Mathar, Mar 31 2025

A382537 Expansion of 1/(1 - x*(1 + 4*x)^(5/2)).

Original entry on oeis.org

1, 1, 11, 51, 211, 1061, 4923, 22765, 107687, 502479, 2352231, 11022911, 51590795, 241559783, 1131156175, 5295875131, 24797055115, 116104311885, 543622665219, 2545347081565, 11917847333151, 55801588711565, 261274518155435, 1223337818786305, 5727913381451455
Offset: 0

Views

Author

Seiichi Manyama, Mar 31 2025

Keywords

Crossrefs

Programs

  • Magma
    R := PowerSeriesRing(Rationals(), 40); f := 1/(1 - x*(1 + 4*x)^(5/2)); seq := [ Coefficient(f, n) : n in [0..30] ];seq; // Vincenzo Librandi, Apr 02 2025
  • Mathematica
    Table[Sum[4^(n-k)*Binomial[5*k/2,n-k],{k,0,n}],{n,0,25}] (* Vincenzo Librandi, Apr 02 2025 *)
  • PARI
    a(n) = sum(k=0, n, 4^(n-k)*binomial(5*k/2, n-k));
    

Formula

a(n) = Sum_{k=0..n} 4^(n-k) * binomial(5*k/2,n-k).
Showing 1-2 of 2 results.