OFFSET
1,4
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..500
FORMULA
a(n) = Max{k : p(n+1)^k < A002110(n)}; a(n) < n is trivial.
EXAMPLE
a(1) = floor(log_3(2)) = 0;
a(2) = floor(log_5(2*3)) = 1;
a(3) = floor(log_7(2*3*5)) = 1;
a(4) = floor(log_11(2*3*5*7)) = 2;
a(5) = floor(log_13(2*3*5*7*11)) = 3;
a(6) = floor(log_17(2*3*5*7*11*13)) = 3;
a(7) = floor(log_19(2*3*5*7*11*13*17)) = 4.
MATHEMATICA
q[x_] := Apply[Times, Table[Prime[w], {w, 1, x}]];
Table[Count[Sign[Table[Prime[w+1]^k-q[w], {k, 1, w}]], -1], {w, 1, 100}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Dec 29 2001
EXTENSIONS
Edited by Jon E. Schoenfield, Sep 05 2017
STATUS
approved