login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A026702 a(n) = Sum_{k=0..floor(n/2} T(n-k, k), T given by A026692. 2
1, 1, 2, 3, 5, 8, 15, 26, 48, 79, 137, 223, 403, 689, 1251, 2088, 3647, 6028, 10775, 18386, 33010, 55460, 96916, 161705, 287199, 490430, 873964, 1475256, 2575673, 4325448, 7646036, 13072664, 23169478, 39254755, 68456542 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..1000

MATHEMATICA

T[_, 0] = 1; T[n_, n_] = 1; T[n_, k_] /; EvenQ[k] && 1 <= k/2 <= Floor[n/4] || EvenQ[n - k] && 1 <= (n - k)/2 <= Floor[n/4] := T[n, k] = T[n - 1, k - 1] + T[n - 2, k - 1] + T[n - 1, k]; T[n_, k_] := T[n, k] = T[n - 1, k - 1] + T[n - 1, k];

a[n_] := Sum[T[n - k, k], {k, 0, Floor[n/2]}];

Table[a[n], {n, 0, 34}] (* Jean-Fran├žois Alcover, Jul 02 2017 *)

CROSSREFS

Sequence in context: A177486 A006982 A054539 * A000047 A101172 A192677

Adjacent sequences:  A026699 A026700 A026701 * A026703 A026704 A026705

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified September 26 05:09 EDT 2017. Contains 292502 sequences.