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 A281551 Prime numbers p such that the decimal representation of its Elias gamma code is also a prime. 1
 3, 23, 41, 47, 59, 89, 101, 149, 179, 227, 317, 347, 353, 383, 389, 479, 503, 599, 821, 887, 929, 977, 1019, 1109, 1229, 1283, 1319, 1511, 1571, 1619, 1667, 1709, 1733, 1787, 1847, 1889, 1907, 1913, 1931, 2207, 2309, 2333, 2357, 2399, 2417, 2459, 2609, 2753, 2789, 2909, 2963, 2999, 3203, 3257, 3299 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Indranil Ghosh, Table of n, a(n) for n = 1..2014 EXAMPLE 59 is in the sequence because the decimal representation of its Elias gamma code is 2011 and both 59 and 2011 are prime numbers. PROG (Python) import math from sympy import isprime def unary(n): ....return "1"*(n-1)+"0" def elias_gamma(n): ....if n ==1: ........return "1" ....k=int(math.log(n, 2)) ....fp=unary(1+k)    #fp is the first part ....sp=n-2**(k)      #sp is the second part ....nb=k             #nb is the number of bits used to store sp in binary ....sp=bin(sp)[2:] ....if len(sp)

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Last modified August 7 23:50 EDT 2022. Contains 355995 sequences. (Running on oeis4.)