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A198188 Primes from the decimal expansion of e, sorted first by the final digit index and then by length. 2
2, 7, 71, 271, 2, 281, 2718281, 2, 5, 59, 5, 2, 3, 23, 523, 4523, 904523, 5, 3, 53, 353, 8284590452353, 2, 7, 360287, 28459045235360287, 7, 47, 8747, 6028747, 8182845904523536028747, 71, 360287471, 8281828459045235360287471, 3, 13, 74713, 82818284590452353602874713 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

M. F. Hasler, Table of n, a(n) for n = 1..655

EXAMPLE

The first digit, 2, is prime, so a(1) = 2.

The second digit, 7, is prime, so a(2) = 7. 27 is not prime.

The third digit, 1, is not prime, but 71 and 271 are, so a(3) = 71 and a(4) = 271.

a(17) shows that "leading zeros are not allowed", i.e., if a prime p is prefixed by a 0 then it is not listed twice. - M. F. Hasler, Feb 05 2012

PROG

(PARI) v=[2, 7, 1, 8, 2, 8, 1, 8, 2, 8, 4, 5, 9, 0, 4, 5, 2, 3, 5, 3, 6, 0, 2, 8, 7, 4, 7, 1, 3]

for(n=1, #v, x=0; p=1; forstep(k=n, 1, -1, x+=p*v[k]; p*=10; if(v[k]&&isprime(x), print1(x", "))))

(PARI) default(realprecision, D=300); for(i=0, D-5, E=exp(1)\.1^i; for(j=1, i+1, ispseudoprime(t=E%10^j) & t!=L print1(L=t", ")))  \\ - M. F. Hasler, Feb 05 2012

CROSSREFS

Cf. A095935.

Sequence in context: A165978 A106917 A188665 * A230459 A267406 A100360

Adjacent sequences:  A198185 A198186 A198187 * A198189 A198190 A198191

KEYWORD

nonn,base

AUTHOR

Franklin T. Adams-Watters, Oct 21 2011

STATUS

approved

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Last modified July 8 01:48 EDT 2020. Contains 335502 sequences. (Running on oeis4.)