A051241 Number of relations with 5 arguments on n nodes.

2, 2147516416, 2355796086371179106111063334323891357095101187404796307182832141733986304

Offset

1,1

Links

Alois P. Heinz, Table of n, a(n) for n = 1..5

Prog

(Python)
from itertools import product
from math import factorial, prod, lcm
from fractions import Fraction
from sympy.utilities.iterables import partitions
def A051241(n): return int(sum(Fraction(1<<sum(prod(r)//lcm(*r)*prod(p[d] for d in r) for r in product(p.keys(), repeat=5)), prod(q**p[q]*factorial(p[q]) for q in p)) for p in partitions(n))) # Chai Wah Wu, Jul 02 2024

Crossrefs

Cf. A000595, A000662, A001377.

Sequence in context: A214600 A325175 A306499 * A094486 A109741 A105759

Adjacent sequences: A051238 A051239 A051240 * A051242 A051243 A051244

Keyword

nonn,bref

Author

Vladeta Jovovic

Status

approved