OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
EXAMPLE
MAPLE
read("transforms") ; A001065 := proc(n) numtheory[sigma](n)-n ; end:
A069250 := proc(n) local pdvs , a, d ; pdvs := numtheory[divisors](n) minus {n} ; a := 0 ; for d in pdvs do a := a+digrev(d) ; od: a ; end:
for n from 4 to 1000 do if not isprime(n) and A001065(n) = A069250(n) then printf("%d, ", n) ; fi; od: # R. J. Mathar, Jul 27 2009
MATHEMATICA
Select[Range[1000], CompositeQ[#]&&DivisorSigma[1, #]-#==Total[IntegerReverse/@ Most[ Divisors[ #]]]&] (* Harvey P. Dale, Oct 12 2023 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Claudio Meller, Jul 21 2009
EXTENSIONS
Keyword:base added by R. J. Mathar, Jul 27 2009
STATUS
approved