OFFSET
1,2
COMMENTS
The ordinal transform of a sequence b(n) is the sequence t(n) = number of values in b(1), ..., b(n) which are equal to b(n).
FORMULA
PROG
(PARI) a(n) = if (n==1, 1, my (f=factor(n), o=vector(vecmax(f[, 2]))); for (i=1, #f~, f[i, 2] = o[f[i, 2]]++); factorback(f))
CROSSREFS
KEYWORD
nonn
AUTHOR
Rémy Sigrist, Sep 20 2018
STATUS
approved