A382099 a(n) is the denominator of the square of the n-th Lagrange number.

1, 1, 25, 169, 841, 289, 7921, 28561, 9409, 54289, 187489, 93025, 970225, 1755625, 2550409, 8392609, 17480761, 32959081, 10452289, 57168721, 82391929, 29953729, 216119401, 821223649, 1119638521, 354681889, 1871514121, 2666792881, 967521025, 5628750625, 9323254249

Offset

1,3

References

John H. Conway and Richard K. Guy, The Book of Numbers, New York: Springer-Verlag, 1996. See p. 187.

Links

Table of n, a(n) for n=1..31.

Formula

a(n) = denominator(9 - 4/A002559(n)^2).

Limit_{n->oo} A382098(n)/a(n) = 9.

Example

5/1 = A002163^2;
8/1 = A010466^2;
221/25 = A200991^2;
1517/169 = A305308^2;
...

Crossrefs

Cf. A002559, A382098 (numerators).

Cf. A002163, A010466, A200991, A305308.

Sequence in context: A080109 A017126 A007204 * A120096 A115330 A213546

Adjacent sequences: A382096 A382097 A382098 * A382100 A382101 A382102

Keyword

nonn,frac

Author

Stefano Spezia, Mar 15 2025

Status

approved