0,2

Row sums of triangle A108358.

Table of n, a(n) for n=0..72.

a(n)=2a(n-1)-3a(n-2)+4a(n-3)-3a(n-4)+2a(n-5)-a(n-6); a(n)=-cos(pi*n/2)/4+(1-n)*sin(pi*n/2)/4+(3n+5)/4; a(n)=sum{k=0..n, mod(sum{j=0..n-k, C(k, j)C(n-j, k)floor((j+2)/2)}, 2)}

Sequence in context: A131798 A206925 A114212 * A057951 A076410 A211509

Adjacent sequences: A108352 A108353 A108354 * A108356 A108357 A108358

easy,nonn

Paul Barry, May 31 2005

approved