A081331 Number of numbers <= n that can be written as sum of two 3-smooth numbers.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 43, 43, 44, 45, 46, 47, 48, 48, 49, 50, 51, 52, 53, 54, 55, 55, 56, 57, 58, 59, 60, 61, 62, 62, 63, 63, 64, 65

Offset: 1

Author

Reinhard Zumkeller, Mar 19 2003

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A081330, A081326, A003586, A081329.

Programs

Mathematica

With[{max = 100}, sm = Select[Range[max], # == Times @@ ({2, 3}^IntegerExponent[#, {2, 3}]) &]; Accumulate@ Table[Boole[IntegerPartitions[n, {2}, sm] != {}], {n, 1, max}]] (* Amiram Eldar, Mar 26 2025 *)