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Search: id:A098515
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| A098515 |
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Least m such that m and m+n are both products of exactly n primes counting multiplicity. |
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+0
5
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| 1, 2, 4, 27, 36, 675, 810, 12393, 7552, 268992, 506240, 6436341, 2440692, 290698227, 455503986, 4897228800, 520575984, 519417147375, 124730265582, 8961777270765, 753891573760, 203558860750848, 51126160064490, 4021771417157632, 1305269217263592, 69131417822953472, 57710779788427264, 1838459534098563045, 63846774162325476
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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4=2*2 & 6=2*3; 27=3*3*3 & 30=2*3*5; 36=2*2*3*3 & 40=2*2*2*5; 675=3*3*3*5*5 & 680=2*2*2*5*17; 810=2*3*3*3*3*5 and 816=2*2*2*2*3*17; etc.
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MATHEMATICA
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f[n_Integer] := Plus @@ Transpose[FactorInteger[n]][[2]]; g[n_] := (k = 2^n; While[a = f[k]; b = f[k + n]; a != b || a != n, k++ ]; k); Do[ Print[ g[n]], {n, 12}]
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CROSSREFS
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Cf. A097978.
Cf. A097978, A135058.
Adjacent sequences: A098512 A098513 A098514 this_sequence A098516 A098517 A098518
Sequence in context: A102996 A095182 A104465 this_sequence A059719 A066228 A110881
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KEYWORD
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nonn
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AUTHOR
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Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 11 2004
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EXTENSIONS
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More terms from David Wasserman (dwasserm(AT)earthlink.net), Feb 20 2008
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