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A266476 Ordinal transform of A266475. 2

%I #15 Dec 23 2021 13:26:11

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

%T 6,1,2,3,6,3,1,4,1,5,6,3,2,1,7,7,8,4,2,2,8,3,5,4,1,4,1,5,6,1,9,7,1,5,

%U 6,8,1,2,2,2,9,6,10,7,1,3,3,3,1,4,10,3,7,5,1,6,11,7,8,4,8,2,1,9,10,9

%N Ordinal transform of A266475.

%C n is the a(n)-th positive integer having value A266475(n).

%H Alois P. Heinz, <a href="/A266476/b266476.txt">Table of n, a(n) for n = 1..20000</a>

%p g:= n-> ((l-> add(l[j]+j-1, j=1..nops(l)))(sort([seq(

%p numtheory[pi](i[1])$i[2], i=ifactors(n)[2])]))):

%p b:= proc() 0 end:

%p a:= proc(n) option remember; local t;

%p t:= g(n); b(t):= b(t)+1

%p end:

%p seq(a(n), n=1..100);

%t g[n_] := Function[l, Sum[l[[j]]+j-1, {j, 1, Length[l]}]][Sort[ Flatten[ Table[ Array[ PrimePi[i[[1]]]&, i[[2]]], {i, FactorInteger[n]}]]]];

%t b[_] = 0;

%t a[n_] := a[n] = With[{t = g[n]}, b[t] = b[t]+1];

%t Table[a[n], {n, 1, 100}] (* _Jean-François Alcover_, Dec 23 2021, after _Alois P. Heinz_ *)

%Y Cf. A266475.

%K nonn,look

%O 1,5

%A _Alois P. Heinz_, Dec 29 2015

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Last modified September 8 07:09 EDT 2024. Contains 375751 sequences. (Running on oeis4.)