A171056 In the sequence of prime numbers, replace all the '9' digits with '7' and vice versa.

2, 3, 5, 9, 11, 13, 19, 17, 23, 27, 31, 39, 41, 43, 49, 53, 57, 61, 69, 91, 93, 97, 83, 87, 79, 101, 103, 109, 107, 113, 129, 131, 139, 137, 147, 151, 159, 163, 169, 193, 197, 181, 171, 173, 179, 177, 211, 223, 229, 227, 233, 237, 241, 251, 259, 263

Offset

1,1

Links

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

Mathematica

FromDigits[IntegerDigits[#] /. {9 -> p, 7 -> q} /. {p -> 7, q -> 9}] & /@ Prime[Range[100]] (* Vincenzo Librandi, Apr 07 2013 *)

Prog

(PARI) a(n)=my(v=[0, 1, 2, 3, 4, 5, 6, 9, 8, 7]); subst(Pol(apply(k->v[k+1], digits(prime(n)))), 'x, 10) \\ Charles R Greathouse IV, Jul 31 2013

Crossrefs

Sequence in context: A078645 A067139 A014657 * A161514 A215779 A140329

Adjacent sequences: A171053 A171054 A171055 * A171057 A171058 A171059

Keyword

nonn,base,easy

Author

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

Status

approved