login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 56th year. In the past year we added 10000 new sequences and reached almost 9000 citations (which often say "discovered thanks to the OEIS").
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A093538 Number of primes between 10^n and 10^n+100. 2
26, 25, 21, 16, 11, 6, 6, 2, 6, 7, 5, 7, 4, 3, 4, 2, 4, 7, 4, 5, 1, 0, 3, 0, 2, 1, 1, 0, 0, 0, 2, 3, 1, 1, 0, 1, 1, 2, 0, 4, 0, 0, 1, 3, 2, 1, 0, 1, 0, 2, 0, 0, 0, 0, 1, 1, 2, 0, 0, 1, 4, 1, 0, 0, 2, 1, 1, 2, 1, 2, 1, 0, 1, 2, 0, 0, 0, 1, 1, 1, 0, 3, 0, 2, 0, 0, 0, 0, 0, 2, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 2, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

Conjecture: a(n) = 1 for infinitely many n, but a(n)>=2 for only finitely many; in fact it may be that a(n)<=1 for n > 775. - Robert Israel, Feb 28 2020

REFERENCES

Marcus du Sautoy, "The Music of the Primes," HarperCollins, NY, 2003, page 6.

LINKS

Robert Israel, Table of n, a(n) for n = 0..4000

EXAMPLE

a(7)=2 because there are 2 primes, 10000019 and 10000079, in the 100 numbers above 10000000.

MAPLE

q:= select(t -> t mod 3 <> 2 and igcd(t, 10)=1, [$1..99]):

f:= proc(n) local T;  T:= 10^n;

numboccur(true, map(t -> isprime(T+t), q))

end proc:

f(0):= 26:

map(f, [$0..100]); # Robert Israel, Feb 28 2020

CROSSREFS

Cf. A323744.

Sequence in context: A072360 A205322 A291470 * A220087 A022982 A023468

Adjacent sequences:  A093535 A093536 A093537 * A093539 A093540 A093541

KEYWORD

nonn

AUTHOR

Jason Earls, May 14 2004

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 30 20:03 EST 2020. Contains 338812 sequences. (Running on oeis4.)