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A256622 Primes p such that the decimal expansion of p remains prime under four iterations of base-10 to base-2 conversion. 3
9632552297, 23971039429, 32460766253, 55325366053, 75883883641, 87824771197, 91754975491, 91989527023, 97696323983 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Jim Fougeron and Farideh Firoozbakht independently found the first term 9632552297.

When does five iterations start?

LINKS

Table of n, a(n) for n=1..9.

Carlos Rivera, Puzzle 280, The Prime Puzzles & Problems Connection.

CROSSREFS

Cf. A065720, A123266, A256621.

Sequence in context: A172610 A225143 A130428 * A022251 A015385 A027570

Adjacent sequences:  A256619 A256620 A256621 * A256623 A256624 A256625

KEYWORD

nonn,base,hard,more

AUTHOR

Sebastian Petzelberger, Apr 07 2015

STATUS

approved

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Last modified April 20 09:59 EDT 2019. Contains 322309 sequences. (Running on oeis4.)