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a(n) = number of i in the range 1 <= i <= n such that b(i)=b(n), where b is the sequence A053615 taken with offset 1.
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%I #8 Mar 30 2012 16:52:07

%S 1,1,2,2,1,3,3,4,2,1,3,5,4,6,4,2,1,3,5,7,5,8,6,4,2,1,3,5,7,9,6,10,8,6,

%T 4,2,1,3,5,7,9,11,7,12,10,8,6,4,2,1,3,5,7,9,11,13,8,14,12,10,8,6,4,2,

%U 1,3,5,7,9,11,13,15,9,16,14,12,10,8,6,4,2,1,3,5,7,9,11,13,15,17,10,18,16,14,12,10,8,6,4,2,1,3,5,7

%N a(n) = number of i in the range 1 <= i <= n such that b(i)=b(n), where b is the sequence A053615 taken with offset 1.

%C This assumes that the word "digit" in the definition in the Wimblik web page is changed to "number".

%H Quoss Wimblik, <a href="http://www.freak-search.com/en/thread/5293952/a_new_numeral_system.">A new numeral system</a>

%p # b[n] = number of i <= n such that a[i]=a[n].

%p FREQ:=proc(a) local b,i,c,n,t1:

%p if whattype(a) <> list then RETURN([]); fi:

%p b:=[];

%p for n from 1 to nops(a) do

%p c:=0; t1:=a[n];

%p for i from 1 to n do if a[i]=t1 then c:=c+1; fi; od:

%p b:=[op(b),c];

%p od;

%p RETURN(b);

%p end:

%p # read A053615 as a list called s1

%p FREQ(s1);

%K nonn

%O 1,3

%A _N. J. A. Sloane_, Nov 22 2011