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A246870 Lesser of the Gridgeman pairs in base 2 in increasing order: pairs of primes palindromic in base 2 which differ only in their middle digits. 3
5, 22541, 296201, 360461, 499151, 514271, 1071937, 1096609, 1298809, 1347877, 1458253, 4404833, 5497829, 5694389, 6824459, 7010219, 7168859, 7267259, 8102639, 17629537, 19525417, 21884773, 23330893, 24364957, 24440413, 24538333, 24735037, 25445443, 28493467 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
Prime Curios!, 181
EXAMPLE
22541 and 22669 are primes with binary representations 101100000001101 and 101100010001101 respectively.
PROG
(Python)
from sympy import isprime
A246870 = []
for n in range(1, 2**17):
....s1 = bin(n)[2:]
....s2 = s1[::-1]
....p1, p2 = int(s1+'0'+s2, base), int(s1+'1'+s2, base)
....if isprime(p1) and isprime(p2):
........A246870.append(p1)
A246870 = sorted(A246870)
CROSSREFS
Sequence in context: A191940 A055380 A201002 * A193366 A347934 A228547
KEYWORD
nonn,base
AUTHOR
Chai Wah Wu, Sep 06 2014
STATUS
approved

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Last modified March 29 05:28 EDT 2024. Contains 371264 sequences. (Running on oeis4.)