A227837 3^a(n) is the highest power of 3 dividing A214551(n).

0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 2, 0, 1, 0, 2, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 3, 0, 0, 0, 2, 0, 0, 0, 0, 2, 0, 2, 1, 0, 0, 0, 0, 1, 0, 1, 0, 1, 3, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 5, 0, 0, 0

Offset: 0

Author

N. J. A. Sloane, Aug 04 2013

Keywords

• nonn

Comments

This is the 3-adic valuation of A214551.

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A000930, A007949, A214551, A227835, A227836.

Programs

Haskell

a227837 = a007949 . a214551  -- Reinhard Zumkeller, Aug 05 2013

Magma

m:=100; A214551:=[i le 2 select 1 else (Self(i)+Self(i-2)) div Gcd(Self(i),Self(i-2)): i in [0..m]]; [Valuation(A214551[n],3): n in [1..m+1]]; // Bruno Berselli, Aug 05 2013

Mathematica

f[l_List] := Append[l, (l[[-1]] + l[[-3]])/GCD[l[[-1]], l[[-3]]]];
A214551[m_] := Nest[f, {1, 1, 1}, m]; IntegerExponent[A214551[200], 3] (* G. C. Greubel, Apr 28 2017 *)