OFFSET
0,4
COMMENTS
Number of 2's in any row of Pascal's triangle (mod 3) whose row number has exactly m 1's and n 2's in its ternary expansion.
a(m,n) is independent of the number of zeros in the ternary expansion of the row number.
a(m,n) gives a non-recursive formula for A227428.
LINKS
Marcus Jaiclin, et al. Pascal's Triangle, Mod 2,3,5
EXAMPLE
Initial 5 X 5 block of array (upper left corner is (0,0), row index m, column index n):
0 1 4 13 40
0 2 8 26 80
0 4 16 52 160
0 8 32 104 320
0 16 64 208 640
Pascal's Triangle (mod 3), row numbers in ternary:
1 <= Row 0, m=0, n=0, 2^(-1)(3^0-1) = #2's = 0
1 1 <= Row 1, m=1, n=0, 2^0(3^0-1) = #2's = 0
1 2 1 <= Row 2, m=0, n=1, 2^(-1)(3^1-1) = #2's = 1
1 0 0 1 <= Row 10, m=1, n=0, 2^0(3^0-1) = #2's = 0
1 1 0 1 1 <= Row 11, m=2, n=0, 2^1(3^0-1) = #2's = 0
1 2 1 1 2 1 <= Row 12, m=1, n=1, 2^0(3^1-1) = #2's = 2
1 0 0 2 0 0 1 <= Row 20, m=0, n=1, 2^(-1)(3^1-1) = #2's = 1
1 1 0 2 2 0 1 1 <= Row 21, m=1, n=1, 2^0(3^1-1) = #2's = 2
1 2 1 2 1 2 1 2 1 <= Row 22, m=0, n=2, 2^(-1)(3^2-1) = #2's = 4
1 0 0 0 0 0 0 0 0 1 <= Row 100, m=1, n=0, 2^0(3^0-1) = #2's = 0
CROSSREFS
KEYWORD
AUTHOR
Marcus Jaiclin, Feb 07 2012
STATUS
approved