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A064118 Numbers n such that the first n digits of e form a prime. 4
1, 3, 7, 85, 1781, 2780, 112280, 155025 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

REFERENCES

C. A. Pickover, The Mathematics of Oz, "2, 271, 2718281", Chapter 95, Camb.Univ.Press, UK 2002.

LINKS

Eric Weisstein's World of Mathematics, e-Prime

Eric Weisstein's World of Mathematics, e-Prime

Eric Weisstein's World of Mathematics, Integer Sequence Primes

EXAMPLE

a(2)=3 because 271 is prime

MATHEMATICA

Do[ If[ PrimeQ[ FromDigits[ RealDigits[ N[ E, n + 10 ], 10, n ][ [ 1 ] ] ] ], Print[ n ] ], {n, 1, 2300} ]

CROSSREFS

Cf. A001113.

Cf. A047658.

Sequence in context: A175236 A045974 A001531 * A082715 A041705 A137130

Adjacent sequences:  A064115 A064116 A064117 * A064119 A064120 A064121

KEYWORD

base,nonn

AUTHOR

Shyam Sunder Gupta (guptass(AT)rediffmail.com), Sep 09 2001

EXTENSIONS

One more term from Robert G. Wilson v (rgwv(AT)rgwv.com), Sep 28 2001

a(6) from Eric Weisstein (eric(AT)weisstein.com), Jan 17 2005

a(7) from Eric W. Weisstein (eric(AT)weisstein.com), Jul 3 2009, a(8) from Eric W. Weisstein (eric(AT)weisstein.com), Oct 11 2010

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Last modified February 16 16:00 EST 2012. Contains 205938 sequences.