A186507 Number of base-3 pyramids of height n.

2, 2, 2, 6, 10, 14, 30, 47, 62, 91, 134, 217, 316, 483, 743, 1118, 1598, 2422, 3616, 5316, 8061, 12284, 18675, 26946, 39146, 59339, 90790, 137602, 206390, 316184

Offset

1,1

Comments

See Caldwell and Rupinski for precise definition.

References

C. K. Caldwell and A. Rupinski, Pyramids of 3-powerful primes, Mathematical Spectrum, 43 (No. 2, 2010/2011), 65-69.

Links

Table of n, a(n) for n=1..30.

Crossrefs

Cf. A186506.

Sequence in context: A291667 A052537 A024945 * A032306 A227847 A058756

Adjacent sequences: A186504 A186505 A186506 * A186508 A186509 A186510

Keyword

base,nonn

Author

N. J. A. Sloane, Feb 22 2011

Status

approved