login
Least nonnegative sequence which does not contain a 5-term equidistant subsequence (a(n+k*d); k=0,1,2,3,4) in arithmetic progression.
2

%I #5 Oct 19 2014 15:50:58

%S 0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,1,1,1,2,2,0,0,0,0,1,0,0,0,0,

%T 1,0,0,0,0,1,0,0,0,0,1,1,1,1,2,2,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0,0,

%U 0,1,1,1,1,2,2,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1,0,0

%N Least nonnegative sequence which does not contain a 5-term equidistant subsequence (a(n+k*d); k=0,1,2,3,4) in arithmetic progression.

%C See A248625 for more information, links and examples.

%o (PARI) a=[];for(n=1,190,a=concat(a,0);while(hasAP(a,5),a[#a]++));a \\ See A248625 for hasAP(). Use concat(a,1) for the "positive integer" variant.

%Y Cf. A248625, A248639, A248627, A229037, A241752.

%K nonn

%O 0,24

%A _M. F. Hasler_, Oct 10 2014