OFFSET
1,1
COMMENTS
a(n) is the smallest area of an integer-sided rectangle able to enclose without contact an integer-sided rectangle of area n. The enclosing rectangle has sides A033676(n)+1 and A033677(n)+1. See the first formula below. - Peter Munn, Apr 26 2019
LINKS
Estonian Math Competitions 2008/2009, problem TS-6, pages 23-24
FORMULA
EXAMPLE
For example, a(6)=12
since 6*7 is not divisible by any number between 6 and 7,
and 6*8 is not divisible by any number between 6 and 8,
and 6*9 is not divisible by any number between 6 and 9,
and 6*10 is not divisible by any number between 6 and 10,
and 6*11 is not divisible by any number between 6 and 11,
but 6*12 is divisible by 9 which is between 6 and 12.
CROSSREFS
KEYWORD
nonn
AUTHOR
Harmel Nestra (harmel.nestra(AT)ut.ee), Jul 30 2009
EXTENSIONS
Formulas extended by Franklin T. Adams-Watters, Aug 06 2009
STATUS
approved