A216245 Sum of 1/a(n)^2 approaches sqrt(3) with partial sums staying below.

1, 2, 2, 3, 3, 11, 26, 109, 1227, 51420, 8988362, 32710914040, 7771377209846338, 490053183865066320353971, 273597849253997654907692972401071423, 337927017741012348216065570192997747462584982737948593

Offset: 1

Author

Michel Marcus, Mar 15 2013

Keywords

• nonn

Crossrefs

Cf. A179332.

Programs

PARI

default(realprecision,10^5);
lista(n) = {x = sqrt(3); for (i=1, n, a = ceil(1/sqrt(x)); print1(a, ", "); x -= 1/a^2;);}