A055235 -id:A055235 - cp's OEIS frontend

A134562 Array T by antidiagonals: T(n,k) = k-th number whose formal base-3 representation has exactly n terms. ("Formal" means that all the nonzero coefficients are 1's.).

1, 3, 2, 9, 4, 5, 27, 6, 7, 8, 81, 10, 11, 14, 17, 243, 12, 13, 16, 23, 26, 729, 18, 15, 20, 25, 44, 53, 2187, 28, 19, 22, 35, 50, 71

Offset: 1

Clark Kimberling, Nov 01 2007

A permutation of the natural numbers. Except for initial terms in some cases, (Row 1) = A000244, (Row 2) = A055235, (Col 1) = A062318. For the analogous base-2 array, see A067576.

			11 = 9 + 1 + 1 is the 3rd largest number (after 5 and 7) that has
a 3-term formal base-3 representation.
Northwest corner:
1 3 9 27 81
2 4 6 10 12
5 7 11 13 15
8 14 16 20 22

Cf. A067576, A000244, A055235, A062318.

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

Original entry on oeis.org

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

Jeremy Gardiner, Oct 08 2011

nonn

Complement of A055235 (sums of two powers of 3)

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

Cf. A055235, A072823.

cp's OEIS Frontend

A134562 Array T by antidiagonals: T(n,k) = k-th number whose formal base-3 representation has exactly n terms. ("Formal" means that all the nonzero coefficients are 1's.).

Views

Author

Keywords

Comments

Examples

Crossrefs