OFFSET
1,9
LINKS
MATHEMATICA
f[n_] := f[n] = {PrimeOmega[n], PrimePi[FactorInteger[n]][[-1, 1]]};
a[n_] := Count[Array[f, n], f[n]];
Array[a, 105] (* Jean-François Alcover, Jan 10 2022 *)
PROG
(PARI)
up_to = 1001;
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; };
A061395(n) = if(1==n, 0, primepi(vecmax(factor(n)[, 1])));
Aux331298(n) = [bigomega(n), A061395(n)];
v331295 = ordinal_transform(vector(up_to, n, Aux331298(n)));
A331295(n) = v331295[n];
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 19 2020
STATUS
approved