A349864 Smallest k such that A349278(k) = n, or 0 if no such k exists.

1, 2, 3, 4, 5, 6, 7, 8, 9, 32, 0, 13, 0, 52, 23, 62, 0, 33, 0, 14, 43, 92, 0, 24, 0, 0, 63, 34, 0, 15, 0, 44, 83, 0, 25, 54, 0, 0, 0, 35, 0, 16, 0, 74, 45, 0, 0, 26, 0, 55, 0, 94, 0, 36, 65, 17, 0, 0, 0, 46, 0, 0, 27, 422, 85, 56, 0, 0, 0, 37, 0, 18, 0, 0, 0, 0, 47, 76, 0, 28, 603, 0, 0, 57, 0, 0, 0, 38, 0, 19

Offset: 1

Author

Bernard Schott, Dec 03 2021

Keywords

• nonn
• base

Comments

Composite numbers m for which a(m) = 0 are in A349865.

Examples

			a(10) = 32 since 2*(2+3) = 10 and no integer du < 32 gives u*(u+d) = 32.
		

Crossrefs

Cf. A349278, A349865.

Cf. A349732 (similar, with first digits).

Formula

If p prime >= 11, a(p) = 0.

Extensions

a(64) and a(81) corrected by Michel Marcus, Dec 03 2021.