A227837 - OEIS

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

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OFFSET

0,14

COMMENTS

This is the 3-adic valuation of A214551.

LINKS

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

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 *)

PROG

(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

CROSSREFS

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

Sequence in context: A357883 A091728 A108069 * A263099 A254001 A089734

Adjacent sequences: A227834 A227835 A227836 * A227838 A227839 A227840

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Aug 04 2013

STATUS

approved