|
| |
|
|
A072100
|
|
Column 2 of the array m(i,1)=m(1,j)=1 m(i,j)=m(i-1,j-1)+m(i-1,j+1) (a(n)=m(n,2)).
|
|
2
| |
|
|
1, 2, 3, 5, 8, 14, 24, 44, 79, 149, 275, 527, 989, 1913, 3629, 7061, 13496, 26366, 50676, 99296, 191674, 376430, 729146, 1434578, 2786656, 5490812, 10691112, 21091712, 41150012, 81266612, 158825372, 313942892, 614483087, 1215563477
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| Partial sums of A001405, to which an additional leading 1 is added. - Paul Barry (pbarry(AT)wit.ie), Oct 12 2004
|
|
|
FORMULA
| G.f.: 1/2*x*(((1+2*x)/(1-2*x))^(1/2)-1)/(1-x)-1. - Vladeta Jovovic (vladeta(AT)eunet.rs), Jan 15 2004
G.f. : (sqrt(1+2x)+1/sqrt(1-2x))/((1-x)(sqrt(1+2x)+sqrt(1-2x))); a(n)=1+sum{k=0..n, binomial(n-1, floor((n-1)/2)}. - Paul Barry (pbarry(AT)wit.ie), Oct 12 2004
|
|
|
CROSSREFS
| Cf. A036256.
Sequence in context: A007059 A079500 A108296 * A104882 A091956 A107480
Adjacent sequences: A072097 A072098 A072099 * A072101 A072102 A072103
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Benoit Cloitre (benoit7848c(AT)orange.fr), Jul 30 2002
|
| |
|
|
