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A117220 Number of partitions of 3-smooth numbers into parts not greater than 3. 7
1, 2, 3, 4, 7, 10, 12, 19, 30, 37, 61, 75, 102, 127, 217, 271, 374, 469, 588, 817, 1027, 1430, 1801, 2269, 3169, 3997, 5043, 5590, 7057, 8911, 12481, 15769, 19927, 22102, 27937, 35317, 44652, 49537, 62641, 79219, 87894, 111169, 140617, 177877, 197377 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

FORMULA

a(n) = A001399(A003586(n)).

EXAMPLE

a(9) = #{3+3+3, 3+3+2+1, 3+3+1+1+1, 3+2+2+2, 3+2+2+1+1, 3+2+1*[4], 3+1*[6],2+2+2+2+1, 2+2+2+1+1+1, 2+2+1*[4], 2+1*[7], 1*[9]} = 12.

MATHEMATICA

s = {}; m = 13; Do[n = 3^k; While[n <= 3^m, AppendTo[s, n]; n*=2], {k, 0, m}]; f[n_] := Round[(n + 3)^2/12]; f /@ Union[s] (* Amiram Eldar, Jan 30 2020 *)

CROSSREFS

Cf. A001399, A003586, A090184, A117221, A117222.

Sequence in context: A051914 A104519 A321684 * A118426 A082008 A105330

Adjacent sequences:  A117217 A117218 A117219 * A117221 A117222 A117223

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Mar 04 2006

STATUS

approved

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Last modified August 10 12:39 EDT 2020. Contains 336379 sequences. (Running on oeis4.)