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A221584
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A sum over partitions (q=20), see first comment.
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9
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1, 19, 399, 7980, 159980, 3199581, 63999600, 1279991601, 25599991620, 511999832020, 10239999832020, 204799996632420, 4095999996640419, 81919999932640800, 1638399999932648400, 32767999998652808799, 655359999998652816380, 13107199999973052976380
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OFFSET
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0,2
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COMMENTS
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Set q=20 and f(m)=q^(m-1)*(q-1), then a(n) is the sum over all partitions P of n over all products Product_{k=1..L} f(m_k) where L is the number of different parts in the partition P=[p_1^m_1, p_2^m_2, ..., p_L^m_L].
Setting q to a prime power gives the sequence "Number of conjugacy classes in GL(n,q)":
Sequences where q is not a prime power:
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LINKS
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PROG
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(PARI)
N=66; x='x+O('x^N);
gf=prod(n=1, N, (1-x^n)/(1-20*x^n) );
v=Vec(gf)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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