

A233794


A bit array representing the primes between 105n102 and 105n+2 among those numbers in the range relatively prime to 6.


1



32596917119, 19221276355, 32294916984, 27056746064, 13260585324, 19153906256, 11044217692, 10628959443, 23930632312, 27274595010, 12929300524, 9758853778, 21477751664, 18735703058, 6820532604, 1946775235, 27961930040, 10687629457, 28253630548, 10613958227
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OFFSET

1,1


COMMENTS

From Riesel: "In a 36bit computer, the primes in an interval from 105k to 105(k+1) can thus be stored in 35 of the 36 bits of a computer word. This string of bits may be reversed and printed out as an integer <2^35. A prime table up to 105 × 100 = 10500 looks rather strange when printed out in this way (see next page) [this sequence]. The reader should compare this with the prime table up to 12553 provided at the end of this book. The table printed there contains slightly more information than the printout on the next page, .... On a 3.5 inch magnetooptical disk, having a storage capacity of 128 Mbytes, there is enough room to store the primes up to about 3,000,000,000 in this way."
a(n) = 0 for almost all n. The first such n is 19151.  Charles R Greathouse IV, Dec 22 2013


REFERENCES

Hans Riesel, Prime Numbers and Computer Methods for Factorization, Second Edition, Birkhäuser, Boston, 1994, pp 810.


LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000


MATHEMATICA

Table[t = Select[Range[105*(n  1) + 3, 105*n + 2], ! IntegerQ[#/2] && ! IntegerQ[#/3] &]; FromDigits[Reverse[Table[If[PrimeQ[i], 1, 0], {i, t}]], 2], {n, 20}] (* T. D. Noe, Dec 30 2013 *)


PROG

(PARI) a(n)=my(s); forstep(n=105*n+2, 105*n102, 1, if(gcd(n, 6)>1, next); s+=s+isprime(n)); s \\ Charles R Greathouse IV, Dec 22 2013


CROSSREFS

Sequence in context: A017639 A234392 A212942 * A202281 A271818 A034655
Adjacent sequences: A233791 A233792 A233793 * A233795 A233796 A233797


KEYWORD

nonn,base


AUTHOR

Robert G. Wilson v, Dec 15 2013


STATUS

approved



