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Search: id:A086684
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| A086684 |
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n! - Sum_{i} p_i!^e_i, where n = Prod_{i} (p_i^e_i). |
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+0
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| 1, 0, 0, 20, 0, 712, 0, 40312, 362844, 3628678, 0, 479001590, 0, 87178286158, 1307674367874, 20922789887984, 0, 6402373705727962, 0, 2432902008176639876, 51090942171709434954, 1124000727777567763198, 0, 620448401733239439359986
(list; graph; listen)
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OFFSET
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1,4
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COMMENT
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a(p)=0 iff p is prime
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EXAMPLE
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a(6)=6!-2!-3!=720-2-6=712
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MATHEMATICA
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g[n_] := Plus @@ Flatten[Table[ # [[1]]! ^ # [[2]], {1}] & /@ FactorInteger[n]]; Table[n! - f[n], {n, 1, 24}]
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PROGRAM
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(PARI) for(i=1, 20, f=factor(i); print1(", "i!-sum(j=1, length(f[, 1]), f[j, 1]!^f[j, 2])))
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CROSSREFS
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Sequence in context: A084029 A008426 A055637 this_sequence A060430 A040404 A040405
Adjacent sequences: A086681 A086682 A086683 this_sequence A086685 A086686 A086687
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KEYWORD
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nonn
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AUTHOR
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Jon Perry (perry(AT)globalnet.co.uk), Jul 28 2003
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EXTENSIONS
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Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com), Aug 16 2003
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