cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A341700 Sum of the primes p satisfying n < p <= 2n.

Original entry on oeis.org

2, 3, 5, 12, 7, 18, 24, 24, 41, 60, 49, 72, 59, 59, 88, 119, 102, 102, 120, 120, 161, 204, 181, 228, 228, 228, 281, 281, 252, 311, 341, 341, 341, 408, 408, 479, 515, 515, 515, 594, 553, 636, 593, 593, 682, 682, 635, 635, 732, 732, 833, 936, 883, 990, 1099, 1099
Offset: 1

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Author

Chai Wah Wu, Feb 17 2021

Keywords

Comments

For n >= 2, a(n) is the sum of the prime numbers appearing in the 2nd row of an n X n square array whose elements are the numbers from 1..n^2, listed in increasing order by rows. - Wesley Ivan Hurt, May 17 2021

Examples

			a(7) = 24 = 11+13 (sum of primes larger than 7 and less than or equal to 14).
		

Crossrefs

Programs

  • Mathematica
    Array[Total@ Select[Range[# + 1, 2 #], PrimeQ] &, 56] (* Michael De Vlieger, Feb 17 2021 *)
  • Python
    from sympy import nextprime
    def A341700(n):
        s, m = 0, nextprime(n)
        while m <= 2*n:
            s += m
            m = nextprime(m)
        return s

Formula

a(n) = A034387(2*n) - A034387(n).
a(n) = A073837(n) if n is not a prime. Otherwise, a(n) = A073837(n)-n.
For n >= 2, a(n) = Sum_{k=(n^2-n+2)/2..(n^2+n-2)/2} A010051(A128076(k)) * A128076(k). - Wesley Ivan Hurt, Jan 08 2022