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

1,2

Links

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

Mathematica

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

Prog

(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
(Magma) [ Seqint([d eq 1 select 2 else d eq 2 select 1 else d : d in Intseq(NthPrime(i))]) : i in [1..100] ]; // Vincenzo Librandi, Sep 17 2025
(Python)
from sympy import prime
def a(n): return int(str(prime(n)).translate({49:50, 50:49}))
print([a(n) for n in range(1, 57)]) # Michael S. Branicky, Sep 17 2025

Crossrefs

Cf. A035043, A180525.

Sequence in context: A182233 A370204 A239282 * A244571 A269721 A084424

Adjacent sequences: A171012 A171013 A171014 * A171016 A171017 A171018

Keyword

nonn,base,easy

Author

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

Status

approved