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.

A382432 a(n) = A074829(2*n-1, n).

Original entry on oeis.org

1, 2, 8, 30, 114, 436, 1676, 6468, 25040, 97190, 378050, 1473254, 5750390, 22476090, 87958306, 344593314, 1351330642, 5303953012, 20834616860, 81900891372, 322168053848, 1268071841744, 4994044075204, 19678407053280, 77578340524444, 305977596195556, 1207325722552016, 4765772559893268
Offset: 1

Views

Author

Michel Marcus, Mar 25 2025

Keywords

Crossrefs

Cf. A074829.

Programs

  • PARI
    T(n, k) = if(k==1 || k==n, fibonacci(n), T(n-1, k-1) + T(n-1, k)); \\ A074829
    a(n) = T(2*n-1, n);
    lista(nn) = my(m=matrix(2*nn)); for (n=1, 2*nn, for (k=1, n, m[n, k] = if(k==1 || k==n, fibonacci(n), m[n-1, k-1] + m[n-1, k]););); vector(nn, i, m[2*i-1, i]);

Formula

D-finite with recurrence (-n+2)*a(n) +(9*n-22)*a(n-1) +(-23*n+72)*a(n-2) +(11*n-58)*a(n-3) +2*(2*n-9)*a(n-4)=0. - R. J. Mathar, Mar 31 2025