A171038 In the sequence of prime numbers, replace all the '7' digits with '4' and vice versa.

2, 3, 5, 4, 11, 13, 14, 19, 23, 29, 31, 34, 71, 73, 74, 53, 59, 61, 64, 41, 43, 49, 83, 89, 94, 101, 103, 104, 109, 113, 124, 131, 134, 139, 179, 151, 154, 163, 164, 143, 149, 181, 191, 193, 194, 199, 211, 223, 224, 229, 233, 239, 271, 251, 254, 263

Offset

1,1

Links

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

Mathematica

fixp[n_]:=FromDigits[IntegerDigits[n]/.{7->a, 4->b}/.{a->4, b->7}]; fixp/@Prime[Range[100]] (* Harvey P. Dale, Apr 25 2011 *)

Prog

(PARI) a(n)=my(v=[0, 1, 2, 3, 7, 5, 6, 4, 8, 9]); subst(Pol(apply(k->v[k+1], digits(prime(n)))), 'x, 10) \\ Charles R Greathouse IV, Jul 25 2013

Crossrefs

Sequence in context: A302849 A193971 A258861 * A023395 A316655 A318848

Adjacent sequences: A171035 A171036 A171037 * A171039 A171040 A171041

Keyword

nonn,base,easy

Author

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

Status

approved