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A065724 Primes p such that the decimal expansion of its base-6 conversion is also prime. 5
2, 3, 5, 7, 19, 37, 67, 79, 97, 103, 127, 157, 163, 193, 229, 283, 307, 337, 439, 487, 547, 571, 601, 631, 643, 673, 733, 751, 757, 853, 877, 907, 937, 1021, 1033, 1039, 1087, 1093, 1117, 1171, 1249, 1279, 1423, 1567, 1627, 1663, 1723, 1753, 1831, 1873 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

In general rebase notation (Marc LeBrun): p(n) = (6) [p] (10).

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..1000

EXAMPLE

E.g., 1627_10 = 11311_6 is prime, and so is 11311_10.

MATHEMATICA

Select[ Range[1900], PrimeQ[ # ] && PrimeQ[ FromDigits[ IntegerDigits[ #, 6]]] & ]

PROG

(PARI) baseE(x, b)= { local(d, e=0, f=1); while (x>0, d=x-b*(x\b); x\=b; e+=d*f; f*=10); return(e) } { n=0; for (m=1, 10^9, p=prime(m); b=baseE(p, 6); if (isprime(b), write("b065724.txt", n++, " ", p); if (n==1000, return)) ) } \\ Harry J. Smith, Oct 27 2009

CROSSREFS

Cf. A065720 up to A065727, A065361.

Sequence in context: A288717 A144561 A215156 * A235620 A289756 A236303

Adjacent sequences:  A065721 A065722 A065723 * A065725 A065726 A065727

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, Nov 15 2001

STATUS

approved

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Last modified August 11 08:50 EDT 2020. Contains 336422 sequences. (Running on oeis4.)