login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A349997
Numbers k such that the number of primes in any interval [j^2,(j+1)^2], j>k, is not less than the number of primes in the interval [k^2,(k+1)^2].
5
1, 7, 11, 17, 18, 26, 27, 32, 46, 50, 56, 58, 85, 88, 92, 137, 143, 145, 152, 157, 178, 188, 194, 200, 201, 208, 225, 232, 253, 263, 279, 297, 327, 331, 339, 360, 433, 451, 485, 506, 536, 541, 607, 696, 708, 717, 768, 799, 801, 806, 904, 913, 1015, 1059, 1110, 1111
OFFSET
1,2
COMMENTS
All terms are empirical subject to the validity of Legendre's conjecture and the boundedness of the scatter band of A014085. See there for further information.
LINKS
FORMULA
A014085(k) >= A014085(a(n)) for all k >= a(n).
EXAMPLE
a(1)=1: the interval [1^2, 2^2] contains A349999(1)=2 primes {2, 3}, and no later interval contains less than 2 primes.
a(2)=7: the interval [7^2, 8^2] contains A349999(2)=3 primes {53, 59, 61}, and no later interval contains less than 3 primes.
a(12)=58: the interval [58^2, 59^2] contains A349999(12)=13 primes {3371, ..., 3469}, and no later interval contains less than 13 primes.
a(13)=85: the interval [85^2, 86^2] contains A349999(13)=16 primes {7229, ..., 7393}, and no later interval contains less than 16 primes.
CROSSREFS
KEYWORD
nonn
AUTHOR
Hugo Pfoertner, Dec 09 2021
STATUS
approved