OFFSET
1,2
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..65537
Antti Karttunen, Sequence plotted up to n=10000, showing the details better
FORMULA
EXAMPLE
a(10) = A007503(10) - 10 = 22 - 10 = 12.
MATHEMATICA
Table[Apply[Plus, DivisorSigma[#, n] & /@ {0, 1}] - n, {n, 79}] (* Michael De Vlieger, Feb 25 2018 *)
PROG
(PARI) A163163(n) = (sigma(n)+numdiv(n)-n); \\ Antti Karttunen, Feb 25 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Juri-Stepan Gerasimov, Jul 22 2009
EXTENSIONS
47 replaced with 37 by R. J. Mathar, Jul 25 2009
STATUS
approved