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.

A097431 Integer part of the hypotenuse of right triangles with consecutive prime legs.

Original entry on oeis.org

3, 5, 8, 13, 17, 21, 25, 29, 37, 42, 48, 55, 59, 63, 70, 79, 84, 90, 97, 101, 107, 114, 121, 131, 140, 144, 148, 152, 157, 169, 182, 189, 195, 203, 212, 217, 226, 233, 240, 248, 254, 263, 271, 275, 280, 290, 307, 318, 322, 326, 333, 339, 347, 359, 367, 376, 381
Offset: 1

Views

Author

Cino Hilliard, Aug 22 2004

Keywords

Examples

			If legs = 3,5 then floor(sqrt(9+25)) = 5, the 2nd entry.
		

Crossrefs

Cf. A069484.

Programs

  • Magma
    [Floor(Sqrt(NthPrime(n)^2 + NthPrime(n+1)^2)): n in [1..60]]; // Vincenzo Librandi, Mar 11 2015
  • Mathematica
    Table[Floor[Sqrt[Prime[n]^2 + Prime[n + 1]^2]], {n, 60}] (* Vincenzo Librandi, Mar 11 2015 *)
    Floor[Sqrt[Total[#^2]]]&/@Partition[Prime[Range[60]],2,1] (* Harvey P. Dale, Mar 30 2024 *)
  • PARI
    a(n) = for(j=1,n,x=prime(j);y=prime(j+1);print1(floor(sqrt(x^2+y^2))","))
    

Formula

a(n) = floor(sqrt(prime(n)^2 + prime(n+1)^2)) = floor(sqrt(A069484(n))).