|
%I #24 Mar 04 2023 02:03:11
%S 3,13,31,37,109,271,283,337,733,739,757,769,811,823,1009,1063,1093,
%T 2269,2281,2467,2521,2539,2551,2917,2953,3001,3037,3163,3169,3187,
%U 3253,3271,6571,6673,6679,6841,7321,7411,7537,7561,7573,8761,8779,8839,9001
%N Primes which can be expressed as a sum of distinct powers of 3.
%C Primes whose base 3 representation contains only 0's and 1's.
%H Harvey P. Dale, <a href="/A077717/b077717.txt">Table of n, a(n) for n = 1..10000</a>
%e 31 = 3^3 + 3 + 1 belongs to this sequence.
%t Select[FromDigits[#,3]&/@Tuples[{0,1},10],PrimeQ] (* _Harvey P. Dale_, Mar 30 2015 *)
%o (PARI) print1(3); forstep(n=3,1e3,2, if(isprime(t=fromdigits(binary(n),3)), print1(", "t))) \\ _Charles R Greathouse IV_, Mar 28 2022
%o (PARI) is_A077717(n)=vecmax(digits(n,3))<2 && isprime(n)
%o select(is_A077717, [1..9111]) \\ _M. F. Hasler_, Feb 15 2023
%o (Python)
%o def is_A077717(n): return A039966(n) and A010051(n) # _M. F. Hasler_, Feb 15 2023
%Y Cf. A020449, A077718, A077719, A077720, A077721, A077722, A077724.
%K nonn,easy
%O 1,1
%A _Amarnath Murthy_, Nov 19 2002
%E More terms from _John W. Layman_, Nov 22 2002
|
