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A180506
The largest palindromic prime dividing n, or 0 if such a prime does not exist.
2
2, 3, 2, 5, 3, 7, 2, 3, 5, 11, 3, 0, 7, 5, 2, 0, 3, 0, 5, 7, 11, 0, 3, 5, 2, 3, 7, 0, 5, 0, 2, 11, 2, 7, 3, 0, 2, 3, 5, 0, 7, 0, 11, 5, 2, 0, 3, 7, 5, 3, 2, 0, 3, 11, 7, 3, 2, 0, 5, 0, 2, 7, 2, 5, 11, 0, 2, 3, 7, 0, 3, 0, 2, 5, 2, 11, 3, 0, 5, 3, 2, 0, 7, 5, 2, 3, 11, 0, 5, 7, 2, 3, 2, 5, 3, 0, 7, 11, 5, 101, 3, 0
OFFSET
2,1
MAPLE
read("transforms") : isA002113 := proc(n) simplify(digrev(n) = n ); end proc:
isA002385 := proc(n) isprime(n) and isA002113(n) ; end proc:
A180506 := proc(n) fs := sort(convert(numtheory[factorset](n), list)) ; for i from 1 to nops(fs) do if isA002385(op(-i, fs)) then return op(-i, fs) ; end if; end do: return 0 ; end proc:
seq(A180506(n), n=2..104) ; # R. J. Mathar, Sep 19 2010
CROSSREFS
Cf. A002385.
Sequence in context: A090662 A088387 A197861 * A273283 A359612 A276440
KEYWORD
base,nonn
AUTHOR
Giovanni Teofilatto, Sep 09 2010
EXTENSIONS
Offset and some values corrected by R. J. Mathar, Sep 19 2010
STATUS
approved