1,2

a(n) = (A005244(n) + 1) / A005244(k) for some k.

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Hofstadter Sequences

Index entries for Hofstadter-type sequences

(Haskell)

a139127 1 = 1

a139127 n = head [y | let z = a005244 n + 1,

y <- reverse $ takeWhile (<= z `div` a020639 z) a005244_list,

z `mod` y == 0]

-- Reinhard Zumkeller, Feb 26 2013

Cf. A020639.

Sequence in context: A128188 A318636 A267582 * A239143 A131319 A108962

Adjacent sequences: A139124 A139125 A139126 * A139128 A139129 A139130

nonn

Reinhard Zumkeller, Apr 09 2008

approved