editing
approved
a(n) = Sum_{p|n, p prime} (n-p)!.
allocated for Wesley Ivan Hurt
a(n) = Sum_{p|n} (n-p)!.
0, 1, 1, 2, 1, 30, 1, 720, 720, 40440, 1, 3991680, 1, 479006640, 482630400, 87178291200, 1, 22230464256000, 1, 6403681380096000, 6402460884019200, 2432902008216556800, 1, 1175091669949317120000, 2432902008176640000, 620448401733245666380800, 620448401733239439360000
1,4
a(A000040(n)) = 1.
a(6) = 30; a(6) = Sum_{p|6} (6-p)! = (6-2)! + (6-3)! = 4*3*2*1 + 3*2*1 = 30.
Cf. A000040, A000142, A062363, A351708, A351709.
allocated
nonn
Wesley Ivan Hurt, Feb 16 2022
