A048284 For k >= A048283(n), there are a(n) numbers expressible as a sum of exactly k-n k-gonal numbers.

2, 4, 6, 7, 9, 9, 12, 14, 14, 15, 17, 19, 20, 20, 21, 23, 26, 26, 27, 27, 29, 31, 33, 34, 35, 35, 35, 37, 39, 41, 42, 44, 44, 44, 44, 46, 48, 51, 52, 54, 54, 54, 54, 54, 55, 57, 61, 62, 63, 64, 64, 65, 65, 65, 67, 69, 72, 73, 75, 75, 76, 77, 77, 77, 77, 78, 81, 84, 85, 86, 87, 88, 90, 90, 90, 90, 90

Offset

0,1

Links

Table of n, a(n) for n=0..76.

Example

For k >= 6, the 2 numbers 2k-1 and 5k-4 are the sum of at best k k-gonal numbers. Hence a(0) = 2.
For k >= 9, the 4 numbers k-1, 2k-2, 4k-4 and 5k-5 are the sum of at best k-1 k-gonal numbers. Hence a(1) = 4.
For k >= 10, the 6 numbers k-2, 2k-3, 3k-4, 4k-5, 5k-6 and 8k-9 are the sum of at best k-2 k-gonal numbers. Hence a(2) = 6.

Crossrefs

Sequence in context: A088458 A177866 A065853 * A026516 A289012 A358768

Adjacent sequences: A048281 A048282 A048283 * A048285 A048286 A048287

Keyword

nonn

Author

David W. Wilson

Extensions

Definition corrected by Jonathan Sondow, Jun 27 2007

Status

approved