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A323076
Number of iterations of map x -> 1+(x-(largest divisor d < x)), starting from x=n, needed to reach a fixed point, which is always either a prime or 1.
5
0, 0, 0, 1, 0, 2, 0, 1, 1, 3, 0, 1, 0, 2, 1, 2, 0, 4, 0, 1, 2, 2, 0, 1, 3, 3, 1, 2, 0, 3, 0, 1, 1, 5, 1, 1, 0, 2, 2, 3, 0, 3, 0, 1, 1, 2, 0, 4, 1, 4, 2, 2, 0, 3, 2, 1, 3, 4, 0, 1, 0, 2, 1, 2, 1, 6, 0, 2, 1, 2, 0, 1, 0, 3, 3, 3, 1, 4, 0, 1, 3, 4, 0, 1, 2, 2, 1, 2, 0, 3, 1, 1, 2, 5, 2, 2, 0, 5, 1, 3, 0, 3, 0, 1, 1
OFFSET
1,6
COMMENTS
Differs from A064918 at n = 25, 48, 51, 69, 75, 81, 85, 94, 95, 99, 100, 111, 115, 121, ...
FORMULA
If n == (1+A060681(n)), then a(n) = 0, otherwise a(n) = 1 + a(1+A060681(n)).
MATHEMATICA
{0}~Join~Array[-2 + Length@ NestWhileList[1 + (# - Divisors[#][[-2]]) &, #, UnsameQ, All] &, 104, 2] (* Michael De Vlieger, Jan 04 2019 *)
PROG
(PARI)
A060681(n) = (n-if(1==n, n, n/vecmin(factor(n)[, 1])));
A323076(n) = { my(nn = 1+A060681(n)); if(nn==n, 0, 1+A323076(nn)); };
CROSSREFS
Cf. A060681, A064918, A323075 (the fixed points reached), A323077, A323079.
Cf. also A039651.
Sequence in context: A326728 A330944 A064918 * A286471 A176079 A067586
KEYWORD
nonn
AUTHOR
Antti Karttunen, Jan 04 2019
STATUS
approved