|
| |
|
|
A284130
|
|
Hosoya triangle of Jacobsthal type, read by rows.
|
|
1
|
|
|
|
1, 1, 1, 3, 1, 3, 5, 3, 3, 5, 11, 5, 9, 5, 11, 21, 11, 15, 15, 11, 21, 43, 21, 33, 25, 33, 21, 43, 85, 43, 63, 55, 55, 63, 43, 85, 171, 85, 129, 105, 121, 105, 129, 85, 171, 341, 171, 255, 215, 231, 231, 215, 255, 171, 341, 683, 341, 513, 425, 473, 441, 473, 425, 513, 341, 683
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,4
|
|
|
LINKS
|
|
|
|
FORMULA
|
|
|
|
EXAMPLE
|
Triangle begins:
1;
1, 1;
3, 1, 3;
5, 3, 3, 5;
11, 5, 9, 5, 11;
21, 11, 15, 15, 11, 21;
...
|
|
|
MATHEMATICA
|
With[{s = Array[(2^# - (-1)^#)/3 &, 150, 0]}, Table[s[[k]] s[[n - k + 1]], {n, Length@ s}, {k, 2, n - 1}]] // Flatten (* Michael De Vlieger, Nov 14 2018, after Joseph Biberstine at A001045 *)
|
|
|
PROG
|
(PARI) a(n) = if(n<2, n, a(n - 1) + 2*a(n - 2));
for(n=0, 15, for(k=1, n, print1(a(k) * a(n - k + 1), ", "); ); print(); ); \\ Indranil Ghosh, Mar 29 2017
|
|
|
CROSSREFS
|
|
|
|
KEYWORD
|
|
|
|
AUTHOR
|
|
|
|
STATUS
|
approved
|
| |
|
|
