A171015 In the sequence of prime numbers, replace all the '2' digits with '1' and vice versa.

1, 3, 5, 7, 22, 23, 27, 29, 13, 19, 32, 37, 42, 43, 47, 53, 59, 62, 67, 72, 73, 79, 83, 89, 97, 202, 203, 207, 209, 223, 217, 232, 237, 239, 249, 252, 257, 263, 267, 273, 279, 282, 292, 293, 297, 299, 122, 113, 117, 119, 133, 139, 142, 152, 157, 163

Offset: 1

Author

N. J. A. Sloane and Vincenzo Librandi, Sep 04 2010

Keywords

• nonn
• base
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Programs

Mathematica

FromDigits[IntegerDigits[#]/.{2->p, 1->q}/.{p->1, q->2}]&/@Prime[Range[100]] (* Vincenzo Librandi, Mar 12 2013 *)

PARI

a(n)=my(v=[0,2,1,3,4,5,6,7,8,9]);subst(Pol(apply(k->v[k+1], digits(prime(n)))),'x,10) \\ Charles R Greathouse IV, Jul 16 2013