OFFSET
1,2
LINKS
T. D. Noe, Table of n, a(n) for n = 1..10000
FORMULA
MAPLE
A132337 := proc(n) r := floor(n^(1/6)) ; A000217(n)-A000540(r); end proc: seq(A132337(n), n=1..40) ; # R. J. Mathar
MATHEMATICA
Accumulate[Table[If[IntegerQ[Surd[n, 6]], 0, n], {n, 60}]] (* Harvey P. Dale, Jun 01 2022 *)
PROG
(PARI) g6(n)=for(x=1, n, r=floor(x^(1/6)); sum6=r^7/7+r^6/2+r^5/2-r^3/6+r/ 42; sn=x* (x+1)/2; print1(sn-sum6", "))
(PARI) A132337(n)=n*(n+1)/2-(1+n=floor(sqrtn(n+.5, 6)))*(2*n+1)*((n^3+2*n^2-1)*n*3+1)*n/42 \\ M. F. Hasler, Oct 09 2010
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Cino Hilliard, Nov 07 2007
EXTENSIONS
Incorrect formula deleted by Jon E. Schoenfield, Jun 12 2010
Incorrect program replaced by R. J. Mathar, Oct 08 2010
Edited by the Assoc. Editors of the OEIS, Oct 12 2010. Thanks to Daniel Mondot for pointing out that the sequence needed editing.
Incorrect linear recurrence removed by Georg Fischer, Apr 11 2019
STATUS
approved