cp's OEIS Frontend

A022911 Arrange the nontrivial binomial coefficients C(m,k) (2 <= k <= m/2) in increasing order (not removing duplicates); record the sequence of m's.

%I A022911 #18 May 23 2019 04:00:55
%S A022911 4,5,6,6,7,8,7,9,10,11,8,12,8,13,9,14,15,16,10,9,17,18,11,19,20,21,10,
%T A022911 12,22,10,23,24,13,25,26,11,27,14,28,29,30,15,11,31,12,32,33,16,34,35,
%U A022911 36,37,17,38,13,39,40,12,18,41,42,43,12,44,19,45,14,46,47,48
%N A022911 Arrange the nontrivial binomial coefficients C(m,k) (2 <= k <= m/2) in increasing order (not removing duplicates); record the sequence of m's.
%C A022911 In case of duplicates, the m values are listed in decreasing order.  Thus a(18)=16 and a(19)=10 corresponding to binomial(16,2)=binomial(10,3)=120. - _Robert Israel_, Sep 18 2018
%H A022911 Robert Israel, <a href="/A022911/b022911.txt">Table of n, a(n) for n = 1..10000</a>
%H A022911 Sean A. Irvine, <a href="https://github.com/archmageirvine/joeis/blob/master/src/irvine/oeis/a022/A022911.java">Java program</a> (github)
%F A022911 A319382(n) = binomial(a(n),A022912(n)). - _Robert Israel_, Sep 18 2018
%p A022911 N:= 10000: # for binomial(n,k) values <= N
%p A022911 Res:= NULL:
%p A022911 for n from 2 while n*(n-1)/2 <= N do
%p A022911   for k from 2 to n/2 do
%p A022911     v:= binomial(n,k);
%p A022911     if v > N then break fi;
%p A022911     Res:= Res,[v,n,k]
%p A022911 od od:
%p A022911 Res:= sort([Res],proc(p,q) if p[1]<>q[1] then  p[1]<q[1]
%p A022911   elif p[2]<>q[2] then p[2]>q[2]
%p A022911   fi end proc):
%p A022911 map(t -> t[2], Res); # _Robert Israel_, Sep 18 2018
%Y A022911 Cf. A003015, A006987, A022912, A319382.
%K A022911 nonn
%O A022911 1,1
%A A022911 _Clark Kimberling_