OFFSET
0,3
EXAMPLE
a(4) = 5 because a(0)*a(1)+a(1)*a(2)+a(2)*a(3)+a(3)*a(4) = 1*1+1*3+3*4+4*5 = 36
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Ayres (jonathan.ayres(AT)btinternet.com), Oct 29 2001
STATUS
approved