The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A108477 A symmetric number triangle based on 2^n. 2
 1, 1, 1, 1, 13, 1, 1, 41, 41, 1, 1, 85, 321, 85, 1, 1, 145, 1289, 1289, 145, 1, 1, 221, 3649, 8989, 3649, 221, 1, 1, 313, 8361, 40081, 40081, 8361, 313, 1, 1, 421, 16641, 134245, 265729, 134245, 16641, 421, 1, 1, 545, 29961, 369305, 1256465, 1256465, 369305 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS Row sums are A108475. Diagonal sums are A108478. LINKS FORMULA Number triangle T(n, k)=if(k<=n, sum{j=0..n, C(2(n-k), j)C(2k, j)2^j}, 0) EXAMPLE Rows begin 1; 1,1; 1,13,1; 1,41,41,1; 1,85,321,85,1; 1,145,1289,1289,145,1; CROSSREFS Sequence in context: A010225 A060361 A141596 * A176204 A176492 A174731 Adjacent sequences:  A108474 A108475 A108476 * A108478 A108479 A108480 KEYWORD easy,nonn,tabl AUTHOR Paul Barry, Jun 04 2005 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
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 29 06:29 EDT 2020. Contains 337425 sequences. (Running on oeis4.)