A049781 a(n) = (b(n) + 1)/2, where b = A000959 (the lucky numbers).

1, 2, 4, 5, 7, 8, 11, 13, 16, 17, 19, 22, 25, 26, 32, 34, 35, 37, 38, 40, 44, 47, 50, 53, 56, 58, 64, 65, 67, 68, 71, 76, 80, 82, 85, 86, 95, 97, 98, 101, 103, 106, 110, 112, 116, 118, 119, 121, 130, 131, 134, 137, 142, 143, 145, 149, 152

Offset: 1

Author

Clark Kimberling

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000
• R. K. Guy, Unsolved Problems in Number Theory, Springer, 2004, C3, pp. 164-165.
• Eric Weisstein's World of Mathematics, Lucky number.
• Wikipedia, Lucky number.

Crossrefs

Cf. A000959.