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A249724 Numbers n such that on row n of Pascal's triangle there is no multiple of 9 which would be less than any (potential) multiple of 4 on the same row. 5

%I

%S 0,1,2,3,4,5,6,7,8,11,12,14,16,17,20,22,23,24,25,26,28,30,32,33,34,35,

%T 36,38,40,41,42,44,48,49,50,51,52,53,56,57,58,60,61,62,64,65,66,67,68,

%U 69,70,71,72,73,74,76,77,78,80,84,86,88,89,92,94,96,97,98,100,101,102,104,105,106,107,108,110,112,113,114,115,116,120,121

%N Numbers n such that on row n of Pascal's triangle there is no multiple of 9 which would be less than any (potential) multiple of 4 on the same row.

%C Disjoint union of {0} and the following sequences: A048278 (gives 7 other cases where there are neither multiples of 4 nor 9 on row n), A249722 (rows where a multiple of 4 is found before a multiple of 9), A249726 (cases where the least term on row n which is multiple of 4 is also multiple of 9, and vice versa, i.e. such a term a multiple of 36).

%C If A249717(n) < 3 then n is included among this sequence. This is a sufficient but not necessary condition, e.g. A249717(25) = 5, but 25 is also included in this sequence.

%H Antti Karttunen, <a href="/A249724/b249724.txt">Table of n, a(n) for n = 1..23590</a>

%o (PARI)

%o A249724list(upto_n) = { my(i=0, n=0, dont_print=0); while(i<upto_n,for(k=0,n\2, if(!(binomial(n,k)%4), i++;write("b249724.txt",i," ",n);dont_print=1;break, if(!(binomial(n,k)%9), dont_print=1;break))); if(!dont_print, i++;write("b249724.txt",i," ",n), dont_print=0); n++); } \\ Ugly code.

%Y Complement: A249723.

%Y Cf. A007318, A052955, A249441, A249695, A249717, A048278, A048645, A051382, A249722, A249726.

%K nonn

%O 1,3

%A _Antti Karttunen_, Nov 04 2014

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Last modified July 10 11:42 EDT 2020. Contains 335576 sequences. (Running on oeis4.)