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A046473
Primes that are palindromic in bases 3 and 10.
9
2, 151, 757, 93739, 7949497, 112969211, 3195269530359625913
OFFSET
1,1
COMMENTS
a(8) > 10^32 if it exists. - Max Alekseyev, Jun 03 2026
EXAMPLE
757_10 = 1001001_3. - Jon E. Schoenfield, Apr 10 2021
MATHEMATICA
f[n_, b_]:=FromDigits[RealDigits[n, b][[1]]]==FromDigits[Reverse[RealDigits[n, b][[1]]]]; lst={}; Do[p=Prime[n]; If[f[p, 3]&&f[p, 10], AppendTo[lst, p]], {n, 8!}]; lst (* Vladimir Joseph Stephan Orlovsky, Sep 25 2009 *)
Select[Prime[Range[65*10^5]], PalindromeQ[#]&&IntegerDigits[#, 3]==Reverse[ IntegerDigits[ #, 3]]&] (* Harvey P. Dale, Jul 20 2024 *)
CROSSREFS
Subsequence of primes of A007633.
Intersection of A002385 and A029971.
Primes that are palindromic in bases 10 and b: A046472 (b=2), A046474 (b=4), A046475 (b=6), A046476 (b=7), A046477 (b=8), A046478 (b=9), A046479 (b=11), A046480 (b=12), A046481 (b=13), A046482 (b=14), A046483 (b=15), A046484 (b=16).
Sequence in context: A157074 A329712 A128350 * A261967 A024245 A113576
KEYWORD
nonn,hard,base,more,changed
AUTHOR
Patrick De Geest, Aug 15 1998
EXTENSIONS
a(7) from Max Alekseyev, Sep 14 2025
STATUS
approved