A004678 - OEIS

%I #26 Sep 08 2022 08:44:33

%S 2,3,11,13,23,31,101,103,113,131,133,211,221,223,233,311,323,331,1003,

%T 1013,1021,1033,1103,1121,1201,1211,1213,1223,1231,1301,1333,2003,

%U 2021,2023,2111,2113,2131,2203,2213,2231,2303,2311,2333,3001,3011,3013

%N Primes written in base 4.

%H Vincenzo Librandi, <a href="/A004678/b004678.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) = A007090(A000040(n)). - _Jonathan Vos Post_, Sep 09 2006

%t FromDigits/@IntegerDigits[Prime[Range[50]],4] (* _Vincenzo Librandi_, Sep 03 2016 *)

%o (PARI) a(n)=subst(Pol(digits(prime(n),4)),'x,10) \\ _Charles R Greathouse IV_, Nov 06 2013

%o (Magma) [Seqint(Intseq(NthPrime(n), 4)): n in [1..60]]; // _G. C. Greubel_, Oct 12 2018

%Y Analogs in other bases: A004676 (base 2), A001363 (base 3), A004679 (base 5), A004680 (base 6), A004681 (base 7), A004682 (base 8), A004683 (base 9), A000040 (base 10), A004684 (base 11).

%Y Cf. A072805 (primes of form 4k+3 written in base 3).

%K nonn,easy,base

%O 1,1

%A _N. J. A. Sloane_

%E More terms from _Vincenzo Librandi_, Sep 03 2016