A215408 Smallest number whose home prime (cf. A037274) is the home prime of exactly n natural numbers.

2, 6, 4, 42, 10, 118, 250, 140, 4206, 3786, 41933, 1798, 722, 87066, 8691, 5978

Offset: 1

Author

Jonathan Sondow, Aug 09 2012

Keywords

• nonn
• base

Comments

The home primes of the sequence are A118756.

Examples

			The home prime of the four numbers 42, 74, 237, and 379 is 379 (for example, 42 = 2*3*7 -> 237 = 3*79 -> 379 which is prime), so a(4) = 42.
		

References

• J. Heleen, Family Numbers: Constructing Primes By Prime Factor Splicing, J. Rec. Math. 28 (1996-97), 116-119.

Links

• P. de Geest, Home Primes < 100 and Beyond
• Eric Weisstein's World of Mathematics, Home Prime.
• Wikipedia, Home prime

Crossrefs

Cf. A037274, A118756, and their cross-references.

Formula

A037274(a(n)) = A118756(n).