Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #22 Dec 21 2020 17:19:11
%S 1,1,21952,5735339,4410944,3553559576,66676466375,7707245470777,
%T 148388768680888,999970000299999,
%U 310810243810243102106210518101010107767,1115341111117511141118670443456
%N Smallest cube that contains exactly n occurrences of the string n.
%C 10^32 < a(10) <= 101010101010100310108799210878085984030872. - _Donovan Johnson_, Jan 16 2013
%C For a(11), I assumed the occurrences could overlap. a(12) <= 1271462121212121201236561213010121209124112392. - _Giovanni Resta_, Feb 09 2013
%e a(2) = 21952 since this is the first cube that contains exactly two 2's.
%o (Python) # a() in A109691
%o print([a(n, POW=3) for n in range(10)]) # _Michael S. Branicky_, Dec 21 2020
%Y Cf. A109690 (4th powers), A109691 (5th powers).
%K base,more,nonn
%O 0,3
%A _Erich Friedman_, Aug 07 2005
%E a(10) from _Giovanni Resta_, Jan 21 2013
%E a(11) from _Giovanni Resta_, Feb 09 2013