A331183 - OEIS

%I #8 Jan 12 2020 23:51:05

%S 1,1,1,2,1,1,1,3,2,2,1,1,1,1,1,4,1,1,1,2,1,2,1,1,1,3,1,1,1,1,1,5,1,3,

%T 1,1,1,4,2,2,1,1,1,2,1,1,1,1,2,1,1,3,1,1,1,1,1,2,1,1,1,1,1,6,1,1,1,3,

%U 1,1,1,1,1,5,1,4,1,1,1,2,1,6,1,1,2,3,2,2,1,1,1,1,1,2,1,1,1,1,2,1,1,1,1,3,1

%N Number of values of k, 1 <= k <= n, with A323898(k) = A323898(n).

%C Ordinal transform of A323898, or equally, of the ordered pair [A000120(n), A083254(n)].

%H Antti Karttunen, <a href="/A331183/b331183.txt">Table of n, a(n) for n = 1..16384</a>

%H Antti Karttunen, <a href="/A331183/a331183.txt">Data supplement: n, a(n) computed for n = 1..65537</a>

%H <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>

%o (PARI) up_to = 16384;

%o ordinal_transform(invec) = { my(om = Map(), outvec = vector(length(invec)), pt); for(i=1, length(invec), if(mapisdefined(om,invec[i]), pt = mapget(om, invec[i]), pt = 0); outvec[i] = (1+pt); mapput(om,invec[i],(1+pt))); outvec; };

%o A083254(n) = (2*eulerphi(n)-n);

%o A323898aux(n) = [hammingweight(n), A083254(n)];

%o v331183 = ordinal_transform(vector(up_to,n,A323898aux(n)));

%o A331183(n) = v331183[n];

%Y Cf. A000120, A083254, A323898.

%Y Cf. also A331182, A331184.

%K nonn

%O 1,4

%A _Antti Karttunen_, Jan 12 2020