OFFSET
1,1
COMMENTS
The function s_g(m) gives the sum of the base-g digits of m.
A term m must have at least 2 prime factors, and the divisor g satisfies the inequalities 1 < g < m^(1/(ord_g(m)+1)) <= sqrt(m), where ord_g(m) gives the maximum exponent e such that g^e divides m.
See Kellner 2019.
LINKS
Bernd C. Kellner, Table of n, a(n) for n = 1..743
Bernd C. Kellner, On primary Carmichael numbers, Integers 22 (2022), Article #A38, 39 pp.; arXiv:1902.11283 [math.NT], 2019.
EXAMPLE
6 is a member, since 2 divides 6 and s_2(6) = 2.
MATHEMATICA
s[n_, g_] := If[n < 1 || g < 2, 0, Plus @@ IntegerDigits[n, g]];
f[n_] := AnyTrue[Divisors[n], s[n, #] >= # &];
Select[Range[1000], f[#] &]
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Bernd C. Kellner, Feb 28 2019
STATUS
approved