login
A238377
Row sums of triangle in A204028.
2
1, 2, 6, 10, 17, 24, 34, 44, 57, 70, 86, 102, 121, 140, 162, 184, 209, 234, 262, 290, 321, 352, 386, 420, 457, 494, 534, 574, 617, 660, 706, 752, 801, 850, 902, 954, 1009, 1064, 1122, 1180
OFFSET
0,2
FORMULA
G.f.: (1+2*x^2)/((1+x)*(1-x)^3)).
a(2*n) = A056109(n).
a(2*n+1) = A049450(n+1) = 2*A000326(n+1).
a(n) = 2*a(n-1) - 2*a(n-3) + a(n-4), a(0) = 1, a(1) = 2, a(2) = 6, a(3) = 10.
EXAMPLE
Triangle in A204028 begins:
1;............................sum = 1
1, 1;.........................sum = 2
1, 4, 1;......................sum = 6
1, 4, 4, 1;...................sum = 10
1, 4, 7, 4, 1;................sum = 17
1, 4, 7, 7, 4, 1;.............sum = 24
1, 4, 7, 10, 7, 4, 1;.........sum = 34
1, 4, 7, 10, 10, 7, 4, 1;.....sum = 44
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Philippe Deléham, Feb 25 2014
EXTENSIONS
Corrected by R. J. Mathar, Aug 08 2015
STATUS
approved