A139388 Nearest integer to (log(744+(12(n^2-1))^3)/Pi)^2.

4, 12, 19, 25, 29, 33, 37, 40, 43, 46, 48, 51, 53, 55, 57, 59, 61, 62, 64, 65, 67, 68, 70, 71, 73, 74, 75, 76, 77, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 90, 91, 92, 93, 94, 95, 95, 96, 97, 98, 98, 99, 100, 101, 101, 102, 103, 103, 104, 105, 105, 106, 106, 107, 108

Offset

1,1

Comments

The well-known integers very close to e^(pi sqrt n) for n=A003173(m) are of the form (12(k^2-1))^3+744. This sequence gives the rounded n-value corresponding to a given k.

References

See A138852 for links, references and more information.

Links

Table of n, a(n) for n=1..66.

Prog

(PARI) A139388(n)=round(log(744+(12*(n^2-1))^3)/Pi)^2)

Crossrefs

Cf. A138851-A138852, A003173, A014708, A056581 and references therein.

Sequence in context: A244433 A086109 A275116 * A300746 A301190 A301184

Adjacent sequences: A139385 A139386 A139387 * A139389 A139390 A139391

Keyword

nonn,easy

Author

M. F. Hasler, Apr 17 2008

Status

approved