A272029 Least number k > n such that the multiplicative and additive digital roots of k are both equal to n.

1111111111, 137, 1111111113, 22, 1157, 123, 1111111117, 179, 11133

Offset: 1

Author

Altug Alkan, Jul 13 2016

Keywords

• nonn
• easy
• base
• fini
• full

Comments

Sequence is trivially finite by definition.

How is the distribution of corresponding digital roots in A064702? This sequence is the result of related observation in limited range.

Examples

			a(5) = 1157 because 1+1+5+7 = 14, 1+4 = 5 and 1*1*5*7 = 35, 3*5 = 15, 1*5 = 5. 1157 is the least number that is greater than 5 with this property.
		

Crossrefs

Cf. A010888, A031347, A064702.