[go: up one dir, main page]

login
A191640
a(n) = floor((-1 + 4^n)/(-1 + 4*n)).
2
1, 2, 5, 17, 53, 178, 606, 2114, 7489, 26886, 97541, 356962, 1315860, 4880644, 18199013, 68174084, 256415957, 967879954, 3665038759, 13917868706, 52988512181, 202209034993, 773282903051, 2962894491691, 11372726331743, 43724268226898, 168358864574597
OFFSET
1,2
LINKS
MATHEMATICA
f[n_] := Floor[(-1+4^n)/(-1+4 n)]
Table[f[n], {n, 1, 40}] (* A191640 *)
PROG
(Magma) [Floor((-1+4^n)/(-1+4*n)): n in [1..30] ]; // Vincenzo Librandi, Sep 10 2011
(Maxima) A191640(n):=floor((-1+4^n)/(-1+4*n))$ makelist(A191640(n), n, 1, 30); /* Martin Ettl, Oct 25 2012 */
CROSSREFS
Cf. A191641.
Sequence in context: A141303 A263678 A133510 * A148408 A002692 A148409
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jun 09 2011
STATUS
approved