OFFSET
1,2
EXAMPLE
a(7) = 44->'101100', {0+k*1: 0<=k<7}: bbbbb0 => 1bbbbb => 10bbbb => bb11bb => bbb100 => 101bbb => bb110b.
a(6) > 44: Although there is an arithmetic progression of length 6 in the binary expansion of 44, it is extendable (to length 7).
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Reinhard Zumkeller, Jan 12 2004
EXTENSIONS
a(12)-a(13) by Álvar Ibeas, Sep 09 2020
a(14)-a(21) by Álvar Ibeas, Sep 12 2020
STATUS
approved