A081812 If n = p_1^e_1 * ... * p_k^e_k, p_1 < ... < p_k primes, then a(n) = Max{ Max(p_i, e_i) }.

2, 3, 2, 5, 3, 7, 3, 3, 5, 11, 3, 13, 7, 5, 4, 17, 3, 19, 5, 7, 11, 23, 3, 5, 13, 3, 7, 29, 5, 31, 5, 11, 17, 7, 3, 37, 19, 13, 5, 41, 7, 43, 11, 5, 23, 47, 4, 7, 5, 17, 13, 53, 3, 11, 7, 19, 29, 59, 5, 61, 31, 7, 6, 13, 11, 67, 17, 23, 7, 71, 3, 73, 37, 5, 19, 11, 13, 79, 5, 4, 41, 83, 7, 17

Offset: 2

Author

Benoit Cloitre, Apr 10 2003

Keywords

• nonn

Links

• Alois P. Heinz, Table of n, a(n) for n = 2..10000

Programs

Maple

a:= n-> max(ifactors(n)[2]):
seq(a(n), n=2..85);  # Alois P. Heinz, Aug 03 2022

Mathematica

a[n_] := Max[Max @@@ FactorInteger[n]];
Table[a[n], {n, 2, 85}] (* Jean-François Alcover, Jan 13 2025 *)

PARI

a(n)=local(f); if(n<1,0,f=factor(n); vecmax(vector(matsize(f)[1],k,max(f[k,1],f[k,2]))))