1,1

It appears that a(n) = A080037[n] = n + Floor[Sqrt[4n-3]] + 2 for n>0.

Eric Weisstein's World of Mathematics, Polyomino.

Cf. A080037.

Sequence in context: A004716 A100373 A123938 this_sequence A049579 A137242 A098015

Adjacent sequences: A121147 A121148 A121149 this_sequence A121151 A121152 A121153

nonn

Alexander Adamchuk (alex(AT)kolmogorov.com), Aug 12 2006