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A090342 Difference between the sums of the prime factors, including multiplicity, of n and those of n + 3. 4
-4, -3, -2, -3, -1, -1, 0, -5, -1, -6, 2, -1, 5, -8, 0, -11, 8, -2, 6, -14, 1, 3, 8, 0, -1, -14, -1, -20, 19, -4, 12, -2, 4, -18, -9, -6, 26, -20, 4, -32, 26, 1, 18, -32, 0, 11, 35, -9, -3, -41, 9, 1, 40, -11, -15, -46, 10, -30, 26, -1, 49, 15, -3, -55, -3, -10, 53, -50, 14, -59, 32, -1, 50, 21, -5, -56, 5, 6, 36, -70, -2, 21, 38 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = A001414(n) - A001414(n+3). - Wesley Ivan Hurt, Aug 29 2016

EXAMPLE

a(24)=0 because 24=2*2*2*3, 27=3*3*3 and (2+2+2+3)-(3+3+3)=0.

MATHEMATICA

Join[{-4}, #[[1]]-#[[4]]&/@(Partition[Table[Total[Flatten[Table[#[[1]], #[[2]]]&/@ FactorInteger[n]]], {n, 2, 90}], 4, 1])] (* Harvey P. Dale, Sep 16 2018 *)

CROSSREFS

Cf. A001414, A090340, A090341, A090343.

Sequence in context: A181061 A329934 A269611 * A010307 A001178 A016501

Adjacent sequences:  A090339 A090340 A090341 * A090343 A090344 A090345

KEYWORD

sign

AUTHOR

Charles K. Layman (cklayman(AT)juno.com), Nov 25 2003

STATUS

approved

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Last modified July 16 09:13 EDT 2020. Contains 335784 sequences. (Running on oeis4.)