A271773 a(1) = 0, then a(n) is the maximum of all 0 < m < n for which n == a(m) (mod m).

0, 1, 2, 1, 4, 1, 6, 3, 5, 1, 10, 1, 12, 9, 2, 1, 16, 1, 18, 7, 11, 1, 22, 5, 13, 3, 20, 1, 28, 1, 30, 21, 17, 7, 8, 1, 36, 25, 5, 1, 40, 1, 42, 39, 23, 1, 46, 7, 16, 33, 14, 1, 52, 11, 48, 19, 29, 1, 58, 1, 60, 15, 38, 13, 54, 1, 66, 45, 7, 1, 70, 1, 72, 27

Offset

1,3

Links

Peter Kagey, Table of n, a(n) for n = 1..10000

Example

a(1) = 0 by definition.
a(2) = 1 because a(1) == 2 (mod 1).
a(3) = 2 because a(2) == 3 (mod 2).
a(4) = 1 because a(1) == 4 (mod 1).
a(5) = 4 because a(4) == 5 (mod 4).
a(6) = 1 because a(1) == 6 (mod 1).
a(7) = 6 because a(6) == 7 (mod 6).
a(8) = 3 because a(3) == 8 (mod 3).

Mathematica

a[1] = 0; a[n_] := a[n] = Max@ Select[Range[n - 1], Mod[n, #] == Mod[a[#], #] &]; Table[a@ n, {n, 75}] (* Michael De Vlieger, Apr 15 2016 *)

Crossrefs

Cf. A269423, A269427, A271530, A271531, A271774.

Sequence in context: A305812 A341857 A292403 * A339602 A277127 A332792

Adjacent sequences: A271770 A271771 A271772 * A271774 A271775 A271776

Keyword

nonn

Author

Peter Kagey, Apr 14 2016

Status

approved