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A139081
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a(n) = (largest prime power dividing n) + (largest prime power dividing (n+1)).
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3
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3, 5, 7, 9, 8, 10, 15, 17, 14, 16, 15, 17, 20, 12, 21, 33, 26, 28, 24, 12, 18, 34, 31, 33, 38, 40, 34, 36, 34, 36, 63, 43, 28, 24, 16, 46, 56, 32, 21, 49, 48, 50, 54, 20, 32, 70, 63, 65, 74, 42, 30, 66, 80, 38, 19, 27, 48, 88, 64, 66, 92, 40, 73, 77, 24, 78, 84, 40, 30
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OFFSET
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1,1
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COMMENTS
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The largest prime-power dividing 12 is 4. The largest prime power dividing 13 is 13. So a(12) = 4+13 = 17.
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LINKS
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Harvey P. Dale, Table of n, a(n) for n = 1..1000
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FORMULA
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a(n) = A034699(n) + A034699(n+1). [From Franklin T. Adams-Watters, Apr 09 2009]
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MATHEMATICA
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With[{c=Table[Max[#[[1]]^#[[2]]&/@FactorInteger[n]], {n, 70}]}, Total/@ Partition[ c, 2, 1]] (* Harvey P. Dale, Nov 18 2014 *)
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PROG
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Contribution from Franklin T. Adams-Watters, Apr 09 2009: (Start)
(PARI) maxpp(n)=local(m, r, pp); m=factor(n); r=1; for(i=1, matsize(m)[1], pp=m[i, 1]^m[i, 2]; if(pp>r, r=pp)); r
vector(80, i, maxpp(i)+maxpp(i+1)) (End)
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CROSSREFS
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Cf. A139082, A139083.
Sequence in context: A317509 A139083 A252002 * A196189 A206543 A274988
Adjacent sequences: A139078 A139079 A139080 * A139082 A139083 A139084
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet, Apr 07 2008
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EXTENSIONS
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More terms from Franklin T. Adams-Watters, Apr 09 2009
Definition clarified by Harvey P. Dale, Nov 18 2014
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STATUS
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approved
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