

A261619


a(n) = floor(prime(n^2) / prime(n)).


1



1, 2, 4, 7, 8, 11, 13, 16, 18, 18, 21, 22, 24, 27, 30, 30, 31, 35, 36, 38, 42, 43, 45, 47, 47, 50, 53, 56, 59, 61, 59, 62, 63, 67, 66, 70, 72, 73, 76, 78, 80, 83, 83, 86, 89, 92, 92, 91, 94, 97, 100, 101, 105, 105, 107, 109, 111, 115, 117, 119
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OFFSET

1,2


COMMENTS

The reason of "/" operation between prime(n^2) and prime(n) is n^2 / n = n.
Sequence is not monotone: 61 = a(30) > a(31) = 59. In the first thousand terms there are 83 less than the preceding term; in the first ten thousand, 865.  Charles R Greathouse IV, Sep 12 2015


LINKS



FORMULA



EXAMPLE

For n=2, a(n) = floor(prime(n^2) / prime(n)) = floor(7/3) = 2.


MATHEMATICA

Table[Floor[Prime[n^2] / Prime[n]], {n, 1, 100}] (* Vincenzo Librandi, May 24 2019 *)


PROG

(PARI) a(n) = floor(prime(n^2) / prime(n));
vector(70, n, a(n))
(PARI) first(n)=my(v=List(), p, k); forprime(q=2, , if(issquare(k++), p=nextprime(p+1); listput(v, q\p); if(#v==n, return(Vec(v))))) \\ Charles R Greathouse IV, Sep 12 2015
(Magma) [NthPrime(n^2) div NthPrime(n): n in [1..70]]; // Vincenzo Librandi, May 24 2019
(Sage) [floor(nth_prime(n^2)/nth_prime(n)) for n in (1..70)] # G. C. Greubel, May 24 2019


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



