A051287 Triangular array T read by rows: T(n,k)=P(n,k,|n-2k|), where P(n,k,c)=number of vectors (x(1),x(2,),...,x(n)) of k 1's and n-k 0's such that x(i)=x(n+1-i) for exactly c values of i.

1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 1, 4, 4, 4, 1, 1, 4, 4, 4, 4, 1, 1, 6, 12, 8, 12, 6, 1, 1, 6, 12, 8, 8, 12, 6, 1, 1, 8, 24, 32, 16, 32, 24, 8, 1, 1, 8, 24, 32, 16, 16, 32, 24, 8, 1, 1, 10, 40, 80, 80, 32, 80, 80, 40, 10, 1, 1, 10, 40, 80, 80, 32, 32, 80

Offset: 0

Author

Clark Kimberling

Keywords

• nonn
• tabl

Comments

P(n,k,n) counts palindromes.

Examples

			Rows: {1}; {1,1}; {1,2,1}; ...
		

Links

• Sean A. Irvine, Java program (github)