OFFSET
1,1
COMMENTS
Different from A023202. Below 1000000 four composites were found [27, 1615, 1885, 218984] satisfying the "sigma(k) + 8 = sigma(k+8)" relation, together with more than 8000 primes. - Labos Elemer, May 23 2000
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
EXAMPLE
sigma(27) + 8 = 48 = sigma(27+8), so 27 is in the sequence.
MATHEMATICA
Select[Range[1300], DivisorSigma[1, #]+8==DivisorSigma[1, #+8]&] (* Harvey P. Dale, Jul 16 2011 *)
PROG
(PARI) is(n)=sigma(n)+8==sigma(n+8) \\ Charles R Greathouse IV, Mar 11 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved