A337276 Index of appearance of 2*n in A336957, or -1 if 2*n never appears.

2, -1, 3, -1, 10, 7, 6, -1, 11, 15, 14, 35, 18, 19, 31, -1, 22, 39, 23, 27, 30, 43, 26, 67, 42, 47, 71, 34, 51, 63, 46, -1, 75, 55, 50, 79, 54, 38, 83, 59, 58, 62, 87, 91, 90, 95, 99, 94, 66, 70, 86, 103, 106, 98, 74, 82, 119, 102, 107, 123, 110, 111, 118, -1, 115, 127, 114, 122, 146, 131, 134

Offset: 1

Author

N. J. A. Sloane, Sep 09 2020

Keywords

• sign

Comments

It is a strong conjecture that 2*n appears in A336957 for all odd n, and it is known that 2^i does not appear for i>1.

Examples

			A336957(14) = 22, so a(11) = 14.
		

Crossrefs

Cf. A336957, A337275.