A127720 Floor of square root of sum of squares of n odd consecutive primes.

3, 5, 9, 14, 19, 25, 31, 39, 48, 57, 68, 80, 90, 102, 115, 129, 143, 157, 173, 187, 203, 220, 237, 256, 275, 294, 313, 331, 350, 372, 394, 418, 440, 465, 488, 513, 538, 564, 590, 616, 642, 670, 697, 724, 751, 780, 811, 843, 873

Offset: 1

Author

Artur Jasinski, Jan 25 2007

Keywords

• nonn

Crossrefs

Cf. A127719, A127721.

Programs

Maple

A024450 := proc(n) local i ; add((ithprime(i))^2,i=1..n) ; end: Ax := proc(n) A024450(n+1)-4 ; end: A000196 := proc(n) floor(sqrt(n)) ; end: A127720 := proc(n) A000196(Ax(n)) ; end: for n from 1 to 30 do printf("%d, ",A127720(n)) ; od ; # R. J. Mathar, Jan 28 2007

Mathematica

a = {}; k = 0; Do[k = k + (Prime[x])^2; AppendTo[a, Floor[Sqrt[k]]], {x, 2, 50}]; a
Module[{nn=50},Floor[Sqrt[#]]&/@Accumulate[Prime[Range[2,nn+1]]^2]] (* Harvey P. Dale, Jul 27 2017 *)

Formula

a(n) = A000196(A024450(n+1) - 4). - R. J. Mathar, Jan 28 2007