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A262049 Sum of the palindromic primes dividing n (with repetition). 3
0, 2, 3, 4, 5, 5, 7, 6, 6, 7, 11, 7, 0, 9, 8, 8, 0, 8, 0, 9, 10, 13, 0, 9, 10, 2, 9, 11, 0, 10, 0, 10, 14, 2, 12, 10, 0, 2, 3, 11, 0, 12, 0, 15, 11, 2, 0, 11, 14, 12, 3, 4, 0, 11, 16, 13, 3, 2, 0, 12, 0, 2, 13, 12, 5, 16, 0, 4, 3, 14, 0, 12, 0, 2, 13 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
a(p)=0 for primes p which are not in A002385.
The first runs of 2, 3 and 4 identical values start at a(5), a(370) and a(2776191), respectively. - Giovanni Resta, Sep 09 2015
LINKS
FORMULA
Let n=product_i p(i)^e(i), then a(n)=sum_{i,p(i) in A002113} e(i)*p(i).
a(n) <= A001414(n).
MAPLE
A262049 := proc(n)
local a, d ;
a := 0 ;
for d in ifactors(n)[2] do
if isA002113(op(1, d)) then
a := a+op(1, d)*op(2, d) ;
end if;
end do:
a ;
end proc:
seq(A262049(n), n=1..120) ;
MATHEMATICA
palQ[n_] := Block[{d = IntegerDigits@ n}, d == Reverse@ d]; {0}~Join~
Table[Total@ Select[Flatten[Table[#1, {#2}] & @@@ FactorInteger@ n], palQ], {n, 2, 75}] (* Michael De Vlieger, Sep 09 2015 *)
Join[{0}, Table[Total[Times@@@Select[FactorInteger[n], PalindromeQ[#[[1]]]&]], {n, 2, 80}]] (* Harvey P. Dale, Sep 05 2022 *)
CROSSREFS
Sequence in context: A360269 A345423 A159303 * A337310 A001414 A134875
KEYWORD
nonn,base
AUTHOR
R. J. Mathar, Sep 09 2015
STATUS
approved

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Last modified March 19 02:51 EDT 2024. Contains 370952 sequences. (Running on oeis4.)