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A209385 Values of the first prefixing digits for Mersenne primes. 1
1, 1, 1, 4, 1, 10, 1, 36, 15, 58, 57, 55, 310, 177, 51, 2389, 973, 532, 1750, 63, 1032, 1240, 3757, 9994, 5854, 12870, 46147, 11923, 17113, 10296, 5977 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

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

Henri Lifchitz and Renaud Lifchitz, PRP Top Records

EXAMPLE

For Mersenne 5 equals to 8191 the first computed prefix is equal to 1 and gives then 18191 which is also a prime.

PROG

PARI for(n=0, 10^6, if(ispseudoprime(n*10^5+2^13-1), print(n", ")));  for the above example corresponding to Mersenne 5

CROSSREFS

Cf. A202136.

Sequence in context: A064947 A059926 A138775 * A121529 A006370 A262370

Adjacent sequences:  A209382 A209383 A209384 * A209386 A209387 A209388

KEYWORD

nonn,base

AUTHOR

Gilbert Mozzo, Mar 07 2012, Mar 18 2012

STATUS

approved

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Last modified September 25 16:29 EDT 2017. Contains 292499 sequences.