OFFSET
1,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..10000 (first 1000 terms from Harvey P. Dale)
FORMULA
a(n) = partial sum of A046992 = partial sum of partial sum of PrimePi(k) = partial sum of partial sum of A000720(k) = Sum_{j=1..n} (Sum_{k=1..j} PrimePi(k)).
a(n) = Sum_{i=1..n} (n+1-i)*pi(i), where pi = A000720. - Ridouane Oudra, Aug 31 2019
MAPLE
A000720 := proc(n) option remember ; numtheory[pi](n) ; end: A046992 := proc(n) option remember ; add( A000720(i), i=1..n) ; end: A137441 := proc(n) add( A046992(i), i=1..n) ; end: seq(A137441(n), n=1..80) ; # R. J. Mathar, Apr 23 2008
# second Maple program:
b:= proc(n) option remember; `if`(n<1, [0$2],
(p-> p+[numtheory[pi](n+1), p[1]])(b(n-1)))
end:
a:= n-> b(n)[2]:
seq(a(n), n=1..49); # Alois P. Heinz, Oct 07 2021
MATHEMATICA
Accumulate[Accumulate[PrimePi[Range[50]]]] (* Harvey P. Dale, Feb 17 2013 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Apr 17 2008
EXTENSIONS
More terms from R. J. Mathar, Apr 23 2008
STATUS
approved