login
A091461
Smallest number containing in its binary representation substrings forming an arithmetic progression exactly of size n.
1
0, 3, 2, 6, 12, 75, 44, 92, 184, 1208, 1256, 4840, 4792, 36055, 9912, 19832, 39664, 563952, 576464, 4496112, 4499184
OFFSET
1,2
COMMENTS
A091460(a(n))=n and A091460(m)<>n for m<a(n).
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
Sequence in context: A175182 A291221 A052616 * A078091 A073883 A248982
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