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%I #11 Dec 18 2015 03:37:25
%S 100111001,110111011,1110111110111,10111101110111101,
%T 100111111111111111001,1111111111111111111,11111111111111111111111,
%U 10111111111101110111111111101,1111110111111111111111110111111
%N Smallest palindromic prime made up of 0's and k 1's, where k = A007310(n), odd numbers not divisible by 3.
%C Smallest palindromic prime with digit sum A007310(n) and using only 0's and 1's.
%H Chai Wah Wu, <a href="/A158214/b158214.txt">Table of n, a(n) for n = 2..167</a>
%o (Python)
%o from __future__ import division
%o from sympy.utilities.iterables import multiset_permutations
%o from sympy import isprime
%o A158214_list = []
%o for i in range(2,101):
%o if i % 6 == 1 or i % 6 == 5:
%o i2 = i//2
%o l = i2
%o flag = True
%o while flag:
%o dlist = '0'*(l-i2) + '1'*i2
%o for d in multiset_permutations(dlist):
%o s = ''.join(d)
%o n = int(s+'1'+s[::-1])
%o if isprime(n):
%o A158214_list.append(n)
%o flag = False
%o break
%o else:
%o l += 1 # _Chai Wah Wu_, Dec 17 2015
%Y Cf. A020449.
%K nonn,base
%O 2,1
%A _Lekraj Beedassy_, Mar 13 2009
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