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URL: https://oeis.org/A179626

⇱ A179626 - OEIS

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A179626
Distance between the n-th abundant number and the nearest prime below it.
1
1, 1, 1, 1, 1, 5, 3, 1, 1, 1, 3, 1, 5, 3, 1, 5, 1, 1, 5, 1, 7, 3, 1, 1, 1, 3, 1, 7, 13, 1, 1, 1, 5, 1, 5, 3, 5, 1, 1, 3, 1, 5, 1, 3, 1, 1, 5, 9, 11, 5, 9, 11, 1, 1, 1, 1, 5, 1, 1, 3, 1, 1, 1, 5, 3, 1, 5, 1, 7, 11, 13, 1, 1, 1, 3, 7, 13, 5, 3, 5, 1, 1, 3, 1, 1, 5, 7, 1, 5, 5, 1, 1, 1, 3, 7, 3, 1, 7, 5, 7, 1, 5, 1
OFFSET
1,6
LINKS
EXAMPLE
The first abundant number is 12. The nearest prime less than 12 is 11, so a(1) = 12 - 11 = 1. Similarly, the sixth abundant number is 36. The nearest prime less than 36 is 31, so a(6) = 36 - 31= 5.
MATHEMATICA
fQ[n_] := DivisorSigma[1, n] > 2 n; f[n_] := n - NextPrime[n, -1]; f@# & /@ Select[ Range@ 450, fQ] (* Robert G. Wilson v, Jul 23 2010 *)
#-NextPrime[#, -1]&/@(Select[Range[500], DivisorSigma[1, #]>2#&]) (* Harvey P. Dale, May 21 2018 *)
CROSSREFS
Sequence in context: A368602 A132199 A111142 * A174965 A159671 A094853
KEYWORD
nonn
AUTHOR
Jason G. Wurtzel, Jul 21 2010
EXTENSIONS
a(15) onwards from Robert G. Wilson v, Jul 23 2010
STATUS
approved