A091889 Number of partitions of n into sums of exactly two distinct powers of 2.

0, 0, 1, 0, 1, 2, 0, 1, 3, 2, 2, 5, 2, 3, 8, 4, 6, 12, 6, 11, 16, 11, 16, 24, 17, 23, 34, 26, 35, 50, 35, 50, 67, 55, 72, 93, 76, 99, 126, 112, 135, 171, 150, 186, 229, 210, 249, 304, 280, 336, 398, 380, 443, 526, 499, 584, 680, 665, 759, 886, 858, 985, 1136, 1123

Offset

1,6

Links

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

Example

a(9)=3: 9 = (2^3+2^0) = (2^2+2^1)+(2^1+2^0) = (2^1+2^0)+(2^1+2^0)+(2^1+2^0).

Mathematica

With[{max = 64}, m = Select[Range[max], DigitCount[#, 2, 1] == 2 &]; a[n_] := Length@ IntegerPartitions[n, n, m]; Array[a, max]] (* Amiram Eldar, Aug 01 2023 *)

Crossrefs

Cf. A018819, A018900, A091890, A000120, A000041, A091893, A091891.

Sequence in context: A177802 A022827 A302764 * A147785 A067591 A097609

Adjacent sequences: A091886 A091887 A091888 * A091890 A091891 A091892

Keyword

nonn

Author

Reinhard Zumkeller, Feb 10 2004

Status

approved