test(N) = /* pentagonal numbers recurrence */
{ my(s,t,p);
  p = vector(N); p[1] = 1;
  for (n=1, N-1,
    s = 0; t = n+1;
    for (k=1, n,
      t -= 2*k-1; /* n+1 - k(3k-1)/2 */
      if (t<=0,break);
      s -= (-1)^k*p[t];
      t -= k;     /* n+1 - k(3k+1)/2 */
      if (t<=0,break);
      s -= (-1)^k*p[t]
    );
    p[n+1] = s;
    if (s != numbpart(n), error([n, s]))
  );
}
test(10^4);

numbpart(0)
numbpart(52602)
numbpart(147007)
numbpart(10^15+2)
partitions(0)
partitions(1)
partitions(9)
partitions(9,3)
partitions(-1)
partitions(5,[3,4],[1,2])
forpart(v=-1,)
forpart(v=5,print(Vec(v)),4,3)
forpart(v=5,print(Vec(v)),[0,5],[2,4])
my(i=0); forpart(x=55,i++); i
forpart(x=9,print(Vec(x)));
forpart(x=11,print(Vec(x)),,5);
forpart(x=12,print(Vec(x)),,[2,6]);
forpart(x=23,print(Vec(x)),[3,6]);
forpart(x=5, print(Vec(x)),[0,3]);
forpart(x=15, print(Vec(x)),[0,3],7);
