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A046355
Composite numbers with only palindromic prime factors whose sum is palindromic (counted with multiplicity).
5
4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 24, 27, 28, 40, 45, 48, 54, 121, 308, 440, 495, 528, 594, 735, 784, 875, 882, 1050, 1120, 1250, 1260, 1331, 1344, 1500, 1512, 1600, 1701, 1800, 1920, 2025, 2048, 2101, 2121, 2160, 2304, 2430, 2525, 2592, 2751, 2916, 3030
OFFSET
1,1
COMMENTS
Subsequence of the numbers k in A046349 such that A262049(k) is in A002113. - R. J. Mathar, Sep 09 2015
LINKS
EXAMPLE
3030 = 2 * 3 * 5 * 101 -> 2 + 3 + 5 + 101 = 111 and 111 is a palindrome.
MAPLE
isA046355 := proc(n)
local sofpp ;
if isA046349(n) then
sofpp := A262049(n) ;
isA002113(sofpp) ;
else
false;
end if;
end proc:
for n from 2 to 400 do
if isA046355(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, 3100], !PrimeQ[#] && And@@palQ/@Join[{Total[Times@@@(x=FactorInteger[#])]}, First/@x]&] (* Jayanta Basu, Jun 05 2013 *)
CROSSREFS
Sequence in context: A246282 A374954 A046352 * A335419 A163122 A329149
KEYWORD
nonn,base
AUTHOR
Patrick De Geest, Jun 15 1998
STATUS
approved