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 A068957 Number of prime divisors of n^n - (n-1)^(n-1), counted with multiplicity. 2
 1, 1, 1, 2, 2, 1, 4, 6, 3, 1, 3, 2, 4, 3, 2, 1, 2, 3, 4, 2, 2, 3, 3, 4, 9, 4, 2, 2, 5, 4, 6, 3, 6, 4, 4, 2, 6, 7, 6, 4, 3, 4, 8, 6, 2, 7, 4, 7, 12, 6, 4, 5, 5, 7, 9, 5, 5, 6, 2, 5, 10, 4, 6, 5, 5, 3, 9, 4, 4, 2, 3, 4, 9, 4, 6, 4, 5, 7, 9, 13, 8, 4, 2, 5, 7 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,4 LINKS FORMULA a(n) = A001222(A007781(n)). EXAMPLE A007781(14) = 10809131718965763 = 3 * 61^2 * 968299894201, therefore a(14) = 4. MATHEMATICA Table[ Apply[ Plus, Transpose[ FactorInteger[n^n - (n - 1)^(n - 1)]] [[ -1]]], {n, 2, 52}] CROSSREFS Cf. A001222, A007781, A068956. Sequence in context: A273903 A048942 A080928 * A119468 A175136 A091869 Adjacent sequences:  A068954 A068955 A068956 * A068958 A068959 A068960 KEYWORD nonn AUTHOR Reinhard Zumkeller, Mar 11 2002 EXTENSIONS Edited and extended by Robert G. Wilson v, Mar 15 2002 a(53)-a(86) from Amiram Eldar, Feb 06 2020 STATUS approved

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Last modified June 15 02:19 EDT 2021. Contains 345042 sequences. (Running on oeis4.)