A335883 The least k for which A335884(k) = n.

1, 3, 5, 11, 23, 47, 109, 229, 457, 1033, 2161, 4703, 10079, 20663, 43223, 94033, 208849, 420457, 872687, 1849921, 3699841, 8748001, 17496001, 36998411

Offset: 0

Author

Antti Karttunen, Jun 29 2020

Keywords

• nonn
• more

Comments

Because A335884 is fully additive and a(1) = 3, we have a(n) <= 3^n and in particular, a(n+1) <= 3*a(n), n > 0 and more generally a(n + m) <= a(n) * a(m) where m, n >= 0. (See also comments in A334099.)

a(16) = 208849 = 457^2 = a(8)*a(8) is the first composite term.

Crossrefs

Cf. A335884.

Formula

For all n >= 0, A335884(a(n)) = n.

Extensions

a(21)-a(23) from Jinyuan Wang, Jul 08 2020