|
| |
|
|
A013941
|
|
a(n) = Sum_{k = 1..n} floor(n/prime(k)^3).
|
|
1
|
|
|
|
0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 10, 11, 11, 11, 11
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,16
|
|
|
LINKS
|
Table of n, a(n) for n=1..75.
|
|
|
FORMULA
|
G.f.: (1/(1 - x))*Sum_{k>=1} x^(prime(k)^3)/(1 - x^(prime(k)^3)). - Ilya Gutkovskiy, Feb 11 2017
|
|
|
MAPLE
|
A013941:=n->add(floor(n/ithprime(k)^3), k=1..n): seq(A013941(n), n=1..150); # Wesley Ivan Hurt, Jan 29 2017
|
|
|
MATHEMATICA
|
Table[Floor[Sum[n/Prime[k]^3, {k, n}]], {n, 75}] (* Alonso del Arte, Jan 29 2017 *)
|
|
|
PROG
|
(PARI) a(n) = sum(k = 1, n, n\prime(k)^3); \\ Michel Marcus, Aug 24 2013
|
|
|
CROSSREFS
|
Cf. A013940.
Sequence in context: A072746 A179528 A105390 * A061798 A318585 A029241
Adjacent sequences: A013938 A013939 A013940 * A013942 A013943 A013944
|
|
|
KEYWORD
|
nonn,easy
|
|
|
AUTHOR
|
N. J. A. Sloane, Henri Lifchitz
|
|
|
STATUS
|
approved
|
| |
|
|
