|
%I #21 Jan 18 2023 19:21:37
%S 11,101,100111001,110111011,111010111,1100011100011,1100101010011,
%T 1101010101011,1110110110111,1110111110111,100110101011001,
%U 101000010000101,101011000110101,101110000011101,110011101110011
%N Palindromic primes containing digits 0 and 1 only. (Palindromic terms in A020449.)
%H Jon E. Schoenfield, <a href="/A100580/b100580.txt">Table of n, a(n) for n = 1..15185</a> (all terms < 10^38; terms 1..200 from T. D. Noe, 201..2385 from Chai Wah Wu)
%e a(3) = 100111001 because 100111001 is the third palindromic prime composed only of 1's and 0's.
%t PalQ[n_]:=FromDigits[Reverse@IntegerDigits[n]]==n; DeleteDuplicates[Flatten[Table[Select[FromDigits /@ Tuples[{0,1},n],PrimeQ[#]&&PalQ[#] &],{n,15}]]] (* _Jayanta Basu_, May 11 2013 *)
%t Select[FromDigits/@Tuples[{0,1},15],PalindromeQ[#]&&PrimeQ[#]&] (* _Harvey P. Dale_, Jan 18 2023 *)
%o (Python)
%o from sympy import isprime
%o A100580_list = [11]
%o for i in range(2,2**16):
%o ....s = format(i,'b')
%o ....x = int(s+s[-2::-1])
%o ....if isprime(x):
%o ........A100580_list.append(x) # _Chai Wah Wu_, Jan 06 2015
%Y Cf. A020449, A002385, A000040, A002113.
%K base,nonn
%O 1,1
%A Chuck Seggelin (seqfan(AT)plastereddragon.com), Nov 29 2004
|
