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A067367 Primes p such that the number of digits in p! is also prime. 2
5, 23, 29, 43, 89, 107, 139, 193, 199, 211, 229, 239, 313, 347, 419, 457, 587, 641, 661, 673, 701, 739, 863, 877, 1091, 1097, 1103, 1217, 1259, 1283, 1361, 1381, 1447, 1493, 1549, 1607, 1609, 1663, 1693, 1741, 1861, 1973, 1987, 2083, 2251, 2351, 2399, 2423 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..450

EXAMPLE

a(1)=5 because 5!=120 has 3 (prime) digits.

MATHEMATICA

Select[ Select[ Range[2500], PrimeQ[ Floor[ Log[10, #! ] + 1]] & ], PrimeQ[ # ] & ]

Select[Prime[Range[400]], PrimeQ[IntegerLength[#!]]&] (* Harvey P. Dale, Mar 08 2018 *)

CROSSREFS

Cf. A035065.

Sequence in context: A018527 A084411 A243458 * A140386 A105880 A163587

Adjacent sequences:  A067364 A067365 A067366 * A067368 A067369 A067370

KEYWORD

nonn,base

AUTHOR

Sudipta Das (juitech(AT)vsnl.net), Feb 23 2002

EXTENSIONS

Edited and extended by Robert G. Wilson v, Feb 28 2002

STATUS

approved

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Last modified May 20 20:16 EDT 2019. Contains 323426 sequences. (Running on oeis4.)