A189559 Least prime k such that x' = k has n solutions, where x' is the arithmetic derivative (A003415) of x.

2, 5, 31, 167, 151, 491, 983, 887, 311, 1151, 1559, 2111, 1031, 2711, 4391, 4271, 3671, 3191, 5351, 9551, 11471, 14759, 8951, 13751, 11831, 5591, 19991, 10391, 15791, 28031, 30071, 37511, 43151, 27191, 40031, 31391, 52631, 53231, 35591, 52391, 50951

Offset: 0

Author

T. D. Noe, Apr 24 2011

Keywords

• nonn

Comments

It is much easier finding composite numbers having many solutions. See A189558. For odd numbers, see A189560.

References

• See A003415.

Links

• Donovan Johnson, Table of n, a(n) for n = 0..200

Crossrefs

Cf. A003415, A099302, A189558, A189560.

Formula

a(n) is the least prime k such that A099302(k) = n.