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

1,1

Links

Table of n, a(n) for n=1..49.

Formula

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

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 *)

Crossrefs

Cf. A127719, A127721.

Sequence in context: A355489 A082874 A266250 * A118002 A069533 A054066

Adjacent sequences: A127717 A127718 A127719 * A127721 A127722 A127723

Keyword

nonn

Author

Artur Jasinski, Jan 25 2007

Status

approved