A196990 Numbers that are not the sum of two powers of 3.

1, 3, 5, 7, 8, 9, 11, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 24, 25, 26, 27, 29, 31, 32, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76

Offset: 1

Author

Jeremy Gardiner, Oct 08 2011

Keywords

• nonn

Comments

Complement of A055235 (sums of two powers of 3)

Examples

			a(2)=3 because 3 cannot be expressed as the sum of two powers of 3
		

Crossrefs

Cf. A055235, A072823.