OFFSET
1,1
COMMENTS
From Amiram Eldar, Apr 23 2021: (Start)
Composite numbers k such that the sum of digits of k (A007953) and the sum of sums of digits of the prime factors of k (taken with multiplicity, A118503) are both even.
The Monica and Suzanne sets were named by Smith (1996) after his two cousins, Monica and Suzanne Hammer. (End)
REFERENCES
József Sándor and Borislav Crstici, Handbook of Number theory II, Kluwer Academic Publishers, 2004, Chapter 4, p. 384.
James J. Tattersall, Elementary Number Theory in Nine Chapters, 2nd ed., Cambridge University Press, 2005, p. 93.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Michael Smith, Cousins of Smith Numbers: Monica and Suzanne Sets, Fibonacci Quarterly, Vol. 34, No. 2 (1996), pp. 102-104.
Eric Weisstein's World of Mathematics, Suzanne Set.
MATHEMATICA
s[n_] := Plus @@ IntegerDigits[n]; f[p_, e_] := e*s[p]; sp[n_] := Plus @@ f @@@ FactorInteger[n]; suz2Q[n_] := CompositeQ[n] && And @@ EvenQ[{s[n], sp[n]}]; Select[Range[300], suz2Q] (* Amiram Eldar, Apr 23 2021 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Eric W. Weisstein, Dec 30 2004
STATUS
approved