A198487 Smallest nonprime positive numbers whose digital product = n, or 0 if impossible.

10, 1, 12, 1113, 4, 15, 6, 117, 8, 9, 25, 0, 26, 0, 27, 35, 28, 0, 36, 0, 45, 371, 0, 0, 38, 55, 0, 39, 74, 0, 56, 0, 48, 0, 0, 57, 49, 0, 0, 0, 58, 0, 76, 0, 0, 95, 0, 0, 68, 77, 255, 0, 0, 0, 69, 0, 78, 0, 0, 0, 256, 0, 0, 791, 88, 0, 0, 0, 0, 0, 275, 0, 98, 0, 0, 355

Offset

0,1

Comments

Zeros appear for n which are a member of A068191.

If the requirement "positive" is dropped, a(0) becomes 0 instead.

Links

Table of n, a(n) for n=0..75.

Example

a(21)=371 because 371 is  the smallest nonprime positive number whose digital product is 21 (3*7*1 = 21).

Crossrefs

Cf. A107698 (smallest primes with digital product n)

Sequence in context: A332803 A073731 A179937 * A099613 A209924 A209926

Adjacent sequences: A198484 A198485 A198486 * A198488 A198489 A198490

Keyword

nonn,base

Author

Jaroslav Krizek, Oct 25 2011

Status

approved