A036954 Primes with digits in {0,1,2} taken as base 3 and converted to base 10.

2, 4, 10, 22, 34, 46, 58, 67, 79, 94, 103, 139, 145, 157, 166, 169, 172, 181, 190, 193, 199, 205, 211, 214, 229, 277, 283, 295, 298, 307, 313, 349, 367, 373, 391, 394, 409, 421, 433, 439, 463, 466, 478, 505, 517, 523, 529, 535, 541, 547, 556, 559, 571, 577

Offset: 1

Author

Patrick De Geest, Jan 04 1999

Keywords

• nonn
• base

Comments

Equivalently: terms of A036953 read in base 3 (and written in base 10). - M. F. Hasler, Jul 25 2015

Equivalently, k such that A007089(k), read literally as a decimal number, is a prime. - N. J. A. Sloane, Feb 17 2023

Examples

			a(n) = 313 is 102121{3}, and 102121{10} is prime.
		

Links

• Iain Fox, Table of n, a(n) for n = 1..10000
• Index entries for sequences related to Most Wanted Primes video

Crossrefs

Cf. A036952-A036964.

Indices of primes in A007089.

Programs

Mathematica

FromDigits[#,3]&/@Select[Tuples[{0,1,2},6],PrimeQ[FromDigits[#]]&] (* Harvey P. Dale, Mar 27 2021 *)

PARI

is(n)=(n%3==1||n==2)&&isprime((n=digits(n,3))*vectorv(#n,i,10^(#n-i))) \\ M. F. Hasler, Jul 25 2015

Formula

a(n) == 1 (mod 3) for all n > 1. - M. F. Hasler, Jul 25 2015

Extensions

Offset corrected to 1 and minor edits by M. F. Hasler, Jul 25 2015