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

Author

M. F. Hasler, Apr 17 2008

Keywords

• nonn
• easy

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.

Crossrefs

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

Programs

Mathematica

Table[Round[(Log[744+(12(n^2-1))^3]/Pi)^2],{n,70}] (* Harvey P. Dale, Mar 26 2025 *)

PARI

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