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A160516
Inverse permutation to A075075.
3
1, 2, 5, 3, 6, 4, 17, 8, 10, 7, 18, 9, 23, 20, 11, 13, 24, 15, 58, 12, 16, 19, 59, 14, 33, 22, 28, 21, 62, 26, 63, 31, 29, 25, 34, 36, 66, 57, 39, 32, 67, 35, 72, 30, 27, 60, 125, 37, 49, 44, 40, 38, 126, 47, 45, 42, 71, 61, 131, 56, 134, 64, 48, 52, 80, 46, 135, 41, 76, 43
OFFSET
1,2
COMMENTS
This is a permutation of the positive integers (provided A075075 really is a permutation).
LINKS
FORMULA
A075075(a(n)) = n.
EXAMPLE
A075075(7) = 10, therefore a(10) = 7.
A075055(17) = 7, therefore a(7) = 17.
MATHEMATICA
f[s_List] := Block[{m = Numerator[s[[ -1]]/s[[ -2]]]}, k = m; While[MemberQ[s, k], k += m]; Append[s, k]]; s = Nest[f, {1, 2}, 200]; Table[ Position[s, n, 1, 1], {n, 70}] // Flatten (* Robert G. Wilson v, May 20 2009 *)
PROG
(Haskell)
import Data.List (elemIndex)
import Data.Maybe (fromJust)
a160516 = (+ 1) . fromJust . (`elemIndex` a075075_list)
-- Reinhard Zumkeller, Dec 19 2012
CROSSREFS
Cf. A185635 (fixed points).
Sequence in context: A367433 A226214 A331212 * A341492 A264105 A024871
KEYWORD
nonn
AUTHOR
Hagen von Eitzen, May 16 2009
STATUS
approved