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Search: id:A126272
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| A126272 |
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a(1)=27; if n = Product p_i^e_i, n>1, then a(n) = Product p_{i+2}^{e_i+2}. |
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| 27, 125, 343, 625, 1331, 42875, 2197, 3125, 2401, 166375, 4913, 214375, 6859, 274625, 456533, 15625, 12167, 300125, 24389, 831875, 753571, 614125, 29791, 1071875, 14641, 857375, 16807, 1373125, 50653, 57066625, 68921, 78125, 1685159
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Analogue of A045967 a(1)=4; if n = Product p_i^e_i, n>1, then a(n) = Product p_{i+1}^{e_i+1}. In a sense, n is the zeroth sequence in a family of sequences, A045967 is the first sequence in a family of sequences, and a(n) is the second sequence in a family of sequences.
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MAPLE
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A126272 := proc(n) local pf, i, p, e, resul ; if n = 1 then 27 ; else pf := ifactors(n)[2] ; resul := 1 ; for i from 1 to nops(pf) do p := op(1, op(i, pf)) ; e := op(2, op(i, pf)) ; resul := resul * nextprime(nextprime(p))^(e+2) ; od ; resul ; fi ; end: for n from 1 to 40 do printf("%d, ", A126272(n)) ; od ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 20 2007
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CROSSREFS
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Cf. A000040, A045967.
Sequence in context: A137800 A125497 A118092 this_sequence A016755 A074100 A082610
Adjacent sequences: A126269 A126270 A126271 this_sequence A126273 A126274 A126275
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KEYWORD
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easy,nonn
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AUTHOR
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Jonathan Vos Post (jvospost2(AT)yahoo.com), Mar 09 2007
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EXTENSIONS
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More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Apr 20 2007
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