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A198778
Primes from merging of 4 successive digits in decimal expansion of Euler-Mascheroni constant A001620.
11
577, 421, 3359, 3593, 5939, 9923, 8677, 2677, 6709, 6947, 6329, 2917, 4951, 1447, 401, 4283, 2417, 6449, 5003, 3733, 3767, 7673, 9491, 2039, 853, 5323, 6211, 4793, 7937, 857, 7057, 29, 3547, 6043, 587, 6733, 7331, 3313, 1399, 7541, 5413, 4139, 8423, 4877, 503, 8431, 3109, 1093, 9973, 3613, 8893, 8933, 17, 7247
OFFSET
1,1
COMMENTS
In contrast to A104938, leading zeros are allowed here, which explains the terms having fewer than 4 digits; e.g., a(32)=29 comes from consecutive digits "...0029..." starting at the 268th decimal digit of gamma (if the initial "0." counts as the first digit). - M. F. Hasler, Oct 31 2011
EXAMPLE
The first four decimal digits of gamma = 0.5772... form the prime 577=a(1).
MAPLE
Digits := 420 ;
for sh from 3 do
p := floor(gamma*10^sh) mod 10000 ;
if isprime(p) then
printf("%d, ", p);
end if;
end do: # R. J. Mathar, Oct 31 2011
MATHEMATICA
(* see A104938 for Mmca code *)
Join[{577}, Select[FromDigits/@Partition[RealDigits[EulerGamma, 10, 1000][[1]], 4, 1], PrimeQ]] (* Harvey P. Dale, May 07 2019 *)
PROG
(PARI) L=10^4; for(i=3, 999, isprime(p=Euler\.1^i%L)&print1(p", ")) \\ M. F. Hasler, Oct 31 2011
KEYWORD
nonn,base
AUTHOR
Harvey P. Dale, Oct 29 2011
STATUS
approved