OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..3020
FORMULA
MAPLE
isA046349 := proc(n)
simplify(isA033620(n) and not isprime(n)) ;
end proc:
for n from 2 to 300 do
if isA046349(n) then
printf("%d, ", n) ;
end if;
end do: # R. J. Mathar, Sep 09 2015
MATHEMATICA
palQ[n_]:=Reverse[x=IntegerDigits[n]]==x; Select[Range[4, 150], !PrimeQ[#]&&And@@palQ/@First/@FactorInteger[#]&] (* Jayanta Basu, Jun 05 2013 *)
Select[Range[200], CompositeQ[#]&&AllTrue[FactorInteger[#][[All, 1]], PalindromeQ]&] (* Harvey P. Dale, May 15 2022 *)
PROG
(Python)
from sympy import isprime, primefactors
def pal(n): s = str(n); return s == s[::-1]
def ok(n): return not isprime(n) and all(pal(f) for f in primefactors(n))
print(list(filter(ok, range(4, 151)))) # Michael S. Branicky, Apr 06 2021
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Patrick De Geest, Jun 15 1998
STATUS
approved