A048284 - OEIS

%I #7 Mar 30 2012 19:00:08

%S 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,

%T 35,35,37,39,41,42,44,44,44,44,46,48,51,52,54,54,54,54,54,55,57,61,62,

%U 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

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

%e 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.

%e 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.

%e 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.

%K nonn

%O 0,1

%A _David W. Wilson_

%E Definition corrected by _Jonathan Sondow_, Jun 27 2007