104489

Appears in sequences

• Numbers k such that sigma(sigma(k)) == phi(k) (mod sigma(k)).at n=25A067204
• Number of connected graphs on n unlabeled nodes with exactly 2 cycles joined along two or more edges but not more than half each cycle and all nodes having degree at most 4.at n=10A305132
• Expansion of e.g.f. ( Product_{k>0} B(x^k)^k )^(1/(1-x)) where B(x) = exp(exp(x)-1) = e.g.f. of Bell numbers.at n=6A356461