OFFSET
1,1
COMMENTS
Known upper bounds for the next terms are: a(11) <= 41, a(12) <= 46, a(13) <= 51, a(14) <= 57, a(15) <= 63, a(16) <= 69, a(17) <= 75, a(18) <= 82, a(19) <= 88, a(20) <= 95. - Arkadiusz Wesolowski, Feb 10 2016
LINKS
Erich Friedman, L's in Squares
EXAMPLE
Illustration:
.
. a - b b a - - - - b b b b - - - - - - - - a b b
. a a b b a a c c c b b b b - - - - - - - a a b b
. b b b b c c c b b a a - - - - - - - b b b b
. b b b b c c c b b a - d d d d - - - b b b b
. c c c c c c - d d d d - c c c c c c
. c c c c c c - d d d d - c c c c c c
. c c c c c c - d d d d - c c c c c c
. d d d d d d d d c c c
. d d d d d d d d c c c
. d d d d d d d d c c c
. d d d d d d d d - - -
.
. 2 4 7 11
.
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Arkadiusz Wesolowski, Feb 06 2013
STATUS
approved