login
A263098
a(n) = Max( tau(k) : k=1,2,3,...,n^2 ) where tau(k) = A000005(k) is the number of divisors of k.
7
1, 3, 4, 6, 8, 9, 10, 12, 12, 12, 16, 16, 16, 18, 18, 20, 20, 20, 24, 24, 24, 24, 24, 24, 24, 24, 30, 30, 32, 32, 32, 32, 32, 32, 32, 36, 36, 36, 36, 36, 40, 40, 40, 40, 40, 40, 40, 40, 40, 40, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 60, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 64, 72
OFFSET
1,2
LINKS
FORMULA
a(n) = A070319(A000290(n)).
MATHEMATICA
Table[Max[DivisorSigma[0, #] & /@ Range[n^2]], {n, 101}] (* Michael De Vlieger, Oct 11 2015 *)
PROG
(PARI)
A070319(n, m=1, s=2)={for(k=s, n, m<numdiv(k)&m=numdiv(k)); m}; \\ This function from M. F. Hasler, Sep 12 2012
A263098 = n -> A070319(n^2); \\ Slow without memoization.
for(n=1, 2080, write("b263098.txt", n, " ", A263098(n)));
(Scheme) (define (A263098 n) (A070319 (A000290 n)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Antti Karttunen, Oct 10 2015
STATUS
approved