A091890 Number of partitions of n into sums of exactly three distinct powers of 2.

0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 2, 0, 0, 0, 1, 1, 1, 3, 2, 0, 1, 3, 3, 2, 5, 2, 1, 1, 5, 6, 3, 9, 5, 4, 5, 10, 9, 8, 13, 8, 10, 8, 16, 17, 15, 22, 18, 18, 20, 25, 28, 27, 34, 31, 32, 33, 44, 49, 44, 64, 53, 56, 61, 71, 77, 77, 100, 88, 94, 99, 123, 125, 132, 162, 147, 154

Offset: 1

Author

Reinhard Zumkeller, Feb 10 2004

Keywords

• nonn

Examples

			a(14)=2: 14 = (2^3+2^2+2^1) = (2^2+2^1+2^0)+(2^2+2^1+2^0).
		

Links

• David A. Corneth, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A014311, A018819, A091889, A000120, A000041, A091893, A091891.

Programs

Mathematica

With[{max = 80}, m = Select[Range[max], DigitCount[#, 2, 1] == 3 &]; a[n_] := Length@ IntegerPartitions[n, n, m]; Array[a, max]] (* Amiram Eldar, Aug 01 2023 *)