login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A228423 Sum of the squared primes less than or equal to n. 0
0, 0, 0, 4, 4, 4, 4, 4, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 13, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 38, 87, 87, 87, 87, 87, 87, 87, 87, 87, 87, 87, 87, 87, 87, 87, 87, 87, 87, 87 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

LINKS

Table of n, a(n) for n=1..67.

FORMULA

a(n) = Sum_{ i <= n | Omega(i) = 2} i * (1 - mu(i)).

EXAMPLE

a(10) = 13; 4 and 9 are the only squared primes less than or equal to 10 and their sum is 13.

MAPLE

with(numtheory); a:=n->add('if'(bigomega(i)=2, i*(1-mobius(i)), 0), i=1..n); seq(a(n), n=1..100);

MATHEMATICA

With[{sp=Prime[Range[10]]^2}, Table[Total[Select[sp, #<=n&]], {n, 100}]] (* Harvey P. Dale, Nov 11 2016 *)

CROSSREFS

Cf. A024450.

Sequence in context: A048760 A287392 A035627 * A165923 A228729 A174444

Adjacent sequences:  A228420 A228421 A228422 * A228424 A228425 A228426

KEYWORD

nonn

AUTHOR

Wesley Ivan Hurt, Nov 09 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 10 15:42 EDT 2020. Contains 335577 sequences. (Running on oeis4.)