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 A235615 Primes whose base-5 representation also is the base-4 representation of a prime. 28
 2, 3, 13, 41, 43, 61, 181, 191, 263, 281, 283, 331, 383, 431, 443, 463, 641, 643, 661, 881, 911, 1063, 1091, 1291, 1303, 1531, 1693, 2083, 2143, 2203, 2293, 2341, 3163, 3181, 3191, 3253, 3343, 3593, 3761, 3931, 4001, 4093, 4391, 4691, 4793, 5011, 5393, 5413, 5441, 6301 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS This sequence is part of the two-dimensional array of sequences based on this same idea for any two different bases b, c > 1. Sequence A235265 and A235266 are the most elementary ones in this list. Sequences A089971, A089981 and A090707 through A090721, and sequences A065720 - A065727, follow the same idea with one base equal to 10. LINKS Robert Price, Table of n, a(n) for n = 1..107268 M. F. Hasler, Primes whose base c expansion is also the base b expansion of a prime EXAMPLE Both 13 = 23_5 and 23_4 = 11 are prime. PROG (PARI) is(p, b=4, c=5)=vecmax(d=digits(p, c))

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Last modified December 2 03:27 EST 2023. Contains 367505 sequences. (Running on oeis4.)