

A007512


Primes of the form floor(e*10^k), i.e., formed by concatenation of an initial segment of the decimal expansion of e.
(Formerly M2184)


12




OFFSET

1,1


COMMENTS

The number of digits in a(n) is given in A064118. This allows us to get larger terms that cannot be displayed here, via the given FORMULA. Sequences A005042, A072952, A115453, A119343, A210704, ... are the analogs for Pi, gamma, sqrt(2), sqrt(3), 3^(1/3), ...  M. F. Hasler, Aug 31 2013


REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

Table of n, a(n) for n=1..4.
Eric Weisstein's World of Mathematics, ePrime
Index entries related to "constant primes".


FORMULA

a(n) = floor(e*10^(A064118(n)1)).  M. F. Hasler, Aug 31 2013


MAPLE

Digits := 110; n0 := evalf(E); for i from 1 to 100 do t1 := trunc(10^i*n0); if isprime(t1) then print(t1); fi; od:


PROG

(PARI) c=exp(1); for(k=0, precision(c), ispseudoprime(c\.1^k) & print1(c\.1^k, ", ")) \\ M. F. Hasler, Sep 01 2013


CROSSREFS

Sequence in context: A188964 A278771 A318171 * A048534 A135696 A008775
Adjacent sequences: A007509 A007510 A007511 * A007513 A007514 A007515


KEYWORD

base,nonn


AUTHOR

N. J. A. Sloane, Robert G. Wilson v, Simon Plouffe


EXTENSIONS

Next term is a 1781digit BPSWprobable prime 2718281828459045235...211151368350627526023.  Randall L. Rathbun (randallr(AT)abac.com), Feb 02 2002
Edited by T. D. Noe, Oct 30 2008
Edited by M. F. Hasler, Aug 31 2013


STATUS

approved



