|
| |
| |
|
|
|
1, 2, 1, 0, 2, 2, 2, 2, 1, 0, 2, 0, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 0, 2, 0, 1, 2, 2, 2, 2, 0, 1, 2, 1, 0, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
COMMENTS
| As usual, "mod 3" means to chose the unique representative in { 0,1,2 } of the equivalence class modulo 3Z.
|
|
|
FORMULA
| a(n) = sum( k=0..n, C(k) ) (mod 3), where C(k) = binomial(2k,k)/(k+1)
a(n) = 1 <=> n = 2 A137821(m) for some m (with A137821(0):=0).
|
|
|
PROG
| (PARI) A137992(n) = lift( sum( k=0, n, binomial( 2*k, k )/(k+1), Mod(0, 3) ))
|
|
|
CROSSREFS
| Cf. A014137, A000108, A137821-A137824, A107755; A014138(n)+1 = a(n+1) (mod 3).
Sequence in context: A190775 A016154 A029343 * A047654 A058487 A062243
Adjacent sequences: A137989 A137990 A137991 * A137993 A137994 A137995
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| M. F. Hasler (www.univ-ag.fr/~mhasler), Mar 16 2008
|
| |
|
|
