A227836 - OEIS

A227836

2^a(n) is the highest power of 2 dividing A214551(n).

0, 0, 0, 1, 0, 2, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 2, 0, 2, 1, 0, 0, 0, 2, 0, 2, 1, 0, 0, 0, 4, 0, 3, 0, 1, 0, 3, 0, 2, 0, 2, 1, 0, 0, 0, 2, 0, 2, 1, 0, 0, 0, 4, 0, 3, 0, 2, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 1, 3, 0, 0, 0, 6, 0, 1, 0, 1, 3, 0, 0, 0, 3, 0, 1, 0, 1, 5, 0, 0, 0, 3, 0, 2, 0

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OFFSET

0,6

COMMENTS

This is the 2-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], 2] (* G. C. Greubel, Apr 28 2017 *)

PROG

(Haskell)

a227836 = a007814 . 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], 2): n in [1..m+1]]; // Bruno Berselli, Aug 05 2013

CROSSREFS

Cf. A000930, A007814, A214551, A227835, A227837.

Sequence in context: A341979 A331838 A361017 * A364042 A033764 A033784

Adjacent sequences: A227833 A227834 A227835 * A227837 A227838 A227839

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Aug 04 2013

STATUS

approved