

A171056


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


3



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
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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



