OFFSET
1,2
COMMENTS
a(n) <= n-3 for n >= 10 (Butcher 1985).
Observation: first 10 terms coincide with A303735. - Omar E. Pol, Oct 04 2018
The preceding observation (by Omar E. Pol) holds also for the 11th term. - Pontus von Brömssen, Apr 05 2023
LINKS
J. C. Butcher, The non-existence of ten stage eighth order explicit Runge-Kutta methods, BIT 25 (1985) 521-540.
MathOverflow, What is the minimum number of stages s required for a Runge-Kutta type numerical method of given order p?, 2019.
Wikipedia, Runge-Kutta methods.
FORMULA
a(n) = max{k; A187102(k)<=n}.
CROSSREFS
KEYWORD
hard,more,nonn
AUTHOR
Pontus von Brömssen, Mar 04 2011
STATUS
approved