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A090887 Irregular primes the indices of whose indices are irregular primes of order two. 0
12923, 19577, 26021, 41203, 41953, 53437, 65309, 68399, 117511, 134731, 137713, 142327, 149861, 155821, 164701, 167887, 192347, 197647, 216901, 224911, 231323, 236063, 246049, 250031, 268999, 271723, 273787, 289543, 317959, 331519, 338141 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The number of primes in this sequence is infinite.

LINKS

Table of n, a(n) for n=1..31.

EXAMPLE

37 is the first irregular prime, 613 is the 37th irregular prime, i.e. iprime[iprime[1]] = 613 and 12923 is the 613th irregular prime.

CROSSREFS

Sequence in context: A162895 A256746 A086004 * A246890 A145333 A190468

Adjacent sequences:  A090884 A090885 A090886 * A090888 A090889 A090890

KEYWORD

easy,nonn

AUTHOR

Cino Hilliard, Feb 12 2004

STATUS

approved

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Last modified February 17 14:12 EST 2018. Contains 299296 sequences. (Running on oeis4.)