OFFSET
1,1
COMMENTS
Subsequence of A130092. - Ivan N. Ianakiev, Sep 17 2019
REFERENCES
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 844.
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
Primefan, The First 2500 Integers Factored (first of 5 pages)
EXAMPLE
10 = 2^1*5^1 has 2 distinct prime factors, hence 2 positive exponents in its prime factorization (although the 1s are often left implicit). 2 is larger than the maximal exponent in 10's prime factorization, which is 1. Therefore, 10 belongs to the sequence.
MATHEMATICA
okQ[n_] := Module[{f = Transpose[FactorInteger[n]][[2]]}, Max[f] < Length[f]]; Select[Range[1000], okQ] (* T. D. Noe, May 24 2012 *)
Select[Range[200], Max[FactorInteger[#][[All, 2]]]<PrimeNu[#]&] (* Harvey P. Dale, Nov 21 2018 *)
PROG
(Haskell)
import Data.List (findIndices)
a212168 n = a212168_list !! (n-1)
a212168_list = map (+ 1) $ findIndices (> 0) a225230_list
-- Reinhard Zumkeller, May 03 2013
(PARI) is(n, f=factor(n))=my(e=f[, 2]); #e && vecmax(e)<#e \\ Charles R Greathouse IV, Jan 09 2022
CROSSREFS
KEYWORD
nonn
AUTHOR
Matthew Vandermast, May 22 2012
STATUS
approved