OFFSET
1,2
COMMENTS
If n > 0 and n is in the sequence, then a(2*n) = 0. Example: 5 is in the sequence, so a(2*5) = a(10) = 0.
Is this a(n) = n*A039982(n-1), n > 1? [R. J. Mathar, Dec 07 2010]
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
FORMULA
MAPLE
A110654 := proc(n) 2*n+1-(-1)^n ; %/4 ; end proc:
A175880 := proc(n) if n <=2 then n; else if type(n, 'even') then n-2*procname(A110654(n)) ; else n; end if; end if; end proc:
seq(A175880(n), n=1..40) ; # R. J. Mathar, Dec 07 2010
PROG
(Haskell)
import Data.List (delete)
a175880 n = a175880_list !! (n-1)
a175880_list = 1 : f [2..] [2..] where
f (x:xs) (y:ys) | x == y = x : (f xs $ delete (2*x) ys)
| otherwise = 0 : (f xs (y:ys))
for_bFile = take 10000 a175880_list
-- Reinhard Zumkeller, Feb 09 2011
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Adriano Caroli, Dec 05 2010
STATUS
approved