A046472 Primes that are palindromic in bases 2 and 10.

3, 5, 7, 313, 7284717174827, 390714505091666190505417093

Offset

1,1

Links

Table of n, a(n) for n=1..6.

P. De Geest, World!Of Palindromic Primes

Example

313_10 = 100111001_2. - Jon E. Schoenfield, Apr 10 2021

Mathematica

Select[Prime[Range[10!]], IntegerDigits[#]==Reverse[IntegerDigits[#]] && IntegerDigits[#, 2]==Reverse[IntegerDigits[#, 2]]&] (* Vladimir Joseph Stephan Orlovsky, Dec 30 2010 *)
p = Sort[Reap[Do[d=IntegerDigits[n]; p1=FromDigits[Join[Most[d], Reverse[d]]]; p2=FromDigits[Join[d, Reverse[d]]]; If[IntegerDigits[p1, 2] == Reverse[IntegerDigits[p1, 2]], Sow[p1]]; If[IntegerDigits[p2, 2] == Reverse[IntegerDigits[p2, 2]], Sow[p2]], {n, 0, 9999999}]][[2, 1]]]; Select[p, PrimeQ]

Crossrefs

Cf. A002385 (palindromic primes), A007632 (palindromes in bases 2 and 10).

Sequence in context: A082756 A268693 A068832 * A065824 A191546 A069463

Adjacent sequences: A046469 A046470 A046471 * A046473 A046474 A046475

Keyword

nonn,hard,base

Author

Patrick De Geest, Aug 15 1998

Extensions

a(6) (from A007632) added by T. D. Noe, Dec 31 2010

Status

approved