A025486 Least k with A025485(k) = n.

0, 3, 5, 10, 26, 170, 7226, 13053770, 42600227803226, 453694852221687377444001770, 51459754733114686962148583993443846186613037940783226

Offset

0,2

Links

Table of n, a(n) for n=0..10.

Formula

For n >= 4, a(n) = a(n-1)^2/4+1.

Conjecture: a(n) = A006892(n+1)+3 for n >= 3. - R. J. Mathar, Apr 23 2007

Crossrefs

Sequence in context: A243516 A243517 A243518 * A011969 A003187 A262306

Adjacent sequences: A025483 A025484 A025485 * A025487 A025488 A025489

Keyword

nonn

Author

David W. Wilson

Extensions

Title corrected and missing a(1)=3 inserted by Sean A. Irvine, Aug 31 2019

Status

approved