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.
%I A351709 #7 Apr 01 2025 18:46:15
%S A351709 0,2,6,2,120,8,5040,2,6,122,39916800,8,6227020800,5042,126,2,
%T A351709 355687428096000,8,121645100408832000,122,5046,39916802,
%U A351709 25852016738884976640000,8,120,6227020802,6,5042,8841761993739701954543616000000,128,8222838654177922817725562880000000
%N A351709 a(n) = Sum_{p|n, p prime} p!.
%C A351709 Inverse Möbius transform of n! * c(n), where c(n) is the characteristic function of primes (A010051). - _Wesley Ivan Hurt_, Apr 01 2025
%F A351709 a(n) = Sum_{d|n} d! * c(d), where c = A010051. - _Wesley Ivan Hurt_, Apr 01 2025
%e A351709 a(6) = 8; a(6) = Sum_{p|6} p! = 2! + 3! = 2*1 + 3*2*1 = 8.
%Y A351709 Cf. A000040, A000142, A010051, A062363, A351708.
%K A351709 nonn
%O A351709 1,2
%A A351709 _Wesley Ivan Hurt_, Feb 16 2022