cp's OEIS Frontend

A267300 Earliest positive increasing sequence having no 5-term subsequence with constant second differences.

%I A267300 #5 Jan 13 2016 00:07:57
%S A267300 0,1,2,3,5,6,7,8,11,13,16,19,20,22,24,30,31,36,45,46,52,55,60,62,63,
%T A267300 66,69,71,75,86,89,92,103,111,115,119,134,137,145,152,163,176,178,179,
%U A267300 196,200,220,223,275,276,278,281,282,284,286,294,304,316,319,326,339,353,360,363,376,379,384,390,402,414,423,429,442
%N A267300 Earliest positive increasing sequence having no 5-term subsequence with constant second differences.
%o A267300 (PARI) A267300(n, show=0, L=5, o=2, v=[0], D=v->v[2..-1]-v[1..-2])={ my(d, m); while( #v<n, show&&print1(v[#v]", "); v=concat(v, v[#v]); while( v[#v]++, forvec( i=vector(L, j, [if(j<L, j, #v), #v]), d=D(vecextract(v, i)); m=o; while(m--&&#Set(d=D(d))>1, ); #Set(d)>1||next(2), 2); break)); v[#v]} \\ _M. F. Hasler_, Jan 12 2016
%Y A267300 Cf. A267301 (positive variant: starting with 1).
%Y A267300 No 3-term AP: A005836 (>=0), A003278 (>0);
%Y A267300 no 4-term AP: A240075 (>=0), A240555 (>0);
%Y A267300 no 5-term AP: A020654 (>=0), A020655 (>0);
%Y A267300 no 6-term AP: A020656 (>=0), A005838 (>0);
%Y A267300 no 7-term AP: A020657 (>=0), A020658 (>0);
%Y A267300 no 8-term AP: A020659 (>=0), A020660 (>0);
%Y A267300 no 9-term AP: A020661 (>=0), A020662 (>0);
%Y A267300 no 10-term AP: A020663 (>=0), A020664 (>0).
%Y A267300 Cf. A240075 and A240555 for sequences avoiding 4-term subsequences with constant second differences.
%Y A267300 Cf. A240556 and A240557 for sequences avoiding 5-term subsequences with constant third differences.
%K A267300 nonn
%O A267300 1,3
%A A267300 _M. F. Hasler_, Jan 12 2016