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Length of the maximal prefix of noncomposite numbers on row n of A249821.
7

%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