OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
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
KEYWORD
sign
AUTHOR
Charles K. Layman (cklayman(AT)juno.com), Nov 25 2003
STATUS
approved