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Search: id:A131995
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| A131995 |
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Number of partitions of n into powers of 2 or of 3. |
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+0
6
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| 1, 2, 3, 5, 6, 9, 11, 16, 20, 26, 32, 42, 50, 62, 74, 92, 108, 131, 153, 184, 213, 251, 288, 339, 387, 448, 511, 589, 666, 761, 857, 976, 1095, 1237, 1384, 1561, 1737, 1946, 2161, 2415, 2672, 2971, 3281, 3640, 4007, 4425, 4860, 5359, 5869, 6446, 7049, 7729, 8428
(list; graph; listen)
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OFFSET
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1,2
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FORMULA
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G.f.=(1-x)/Product((1-x^(2^k))(1-x^(3^k)), k=0..infinity) (offset 0). - Emeric Deutsch (deutsch(AT)duke.poly.edu), Aug 26 2007
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EXAMPLE
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a(10) = #{9+1, 8+2, 8+1+1, 4+4+2, 4+4+1+1, 4+3+3, 4+3+2+1,
4+3+1+1+1, 4+2+2+2, 4+2+2+1+1, 4+2+1+1+1+1, 4+1+1+1+1+1+1, 3+3+3+1,
3+3+2+2, 3+3+2+1+1, 3+3+1+1+1+1, 3+2+2+2+1, 3+2+2+1+1+1,
3+2+1+1+1+1+1, 3+1+1+1+1+1+1+1, 2+2+2+2+2, 2+2+2+2+1+1, 2+2+2+1+1+1+1,
2+2+1+1+1+1+1+1, 2+1+1+1+1+1+1+1+1, 1+1+1+1+1+1+1+1+1+1} = 26.
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MAPLE
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g:=(1-x)/(product((1-x^(2^k))*(1-x^(3^k)), k=0..10)): gser:=series(g, x=0, 60): seq(coeff(gser, x, n), n=1..53); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Aug 26 2007
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CROSSREFS
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Cf. A018819, A062051, A023893, A000041, A131996.
Sequence in context: A008769 A115270 A027588 this_sequence A060714 A032718 A086191
Adjacent sequences: A131992 A131993 A131994 this_sequence A131996 A131997 A131998
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KEYWORD
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nonn
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AUTHOR
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Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Aug 06 2007
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