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.

A051241 Number of relations with 5 arguments on n nodes.

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%I A051241 #13 Jul 02 2024 15:26:45
%S A051241 2,2147516416,
%T A051241 2355796086371179106111063334323891357095101187404796307182832141733986304
%N A051241 Number of relations with 5 arguments on n nodes.
%H A051241 Alois P. Heinz, <a href="/A051241/b051241.txt">Table of n, a(n) for n = 1..5</a>
%o A051241 (Python)
%o A051241 from itertools import product
%o A051241 from math import factorial, prod, lcm
%o A051241 from fractions import Fraction
%o A051241 from sympy.utilities.iterables import partitions
%o A051241 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
%Y A051241 Cf. A000595, A000662, A001377.
%K A051241 nonn,bref
%O A051241 1,1
%A A051241 _Vladeta Jovovic_