%I #12 Apr 02 2017 17:25:30
%S 3,4,8,13,27,35,56,66,92,138,153,209,252,271,316,395,472,503,592,657,
%T 686,791,865,978,1140,1228,1269,1355,1396,1495,1848,1946,2110,2158,
%U 2456,2513,2694,2879,3006,3203,3397,3472,3827,3903,4046,4120,4582,5060,5227,5308,5473,5742,5831,6268,6542,6815,7106,7196,7487,7685,7783,8294,9028,9247,9353,9567,10350
%N Length of the maximal prefix of noncomposite numbers on row n of A249821.
%C a(n) = Length of the initial fixed portion of the permutation at row n of A251721 & A251722.
%C Also, for n > 1, the length of the maximal increasing prefix on row n of A249821.
%F a(n) = A054272(n) + 1.
%F a(n) = A250474(n) - 1.
%F a(n) = 2 + A000879(n) - n.
%o (define (A250473 n) (- (A250474 n) 1))
%Y One more than A054272.
%Y One less than A250474.
%Y Cf. A000879, A249821, A251721, A251722.
%K nonn
%O 1,1
%A _Antti Karttunen_, Nov 23 2014