A051011 -id:A051011 - cp's OEIS frontend

A051010 Triangle T(m,n) giving of number of steps in the Euclidean algorithm for gcd(m,n) with 0<=m

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

Offset: 1

Eric W. Weisstein

T. D. Noe, Rows n=1..100 of triangle, flattened
Eric Weisstein's World of Mathematics, Euclidean Algorithm.

Cf. A034883, A051011, A051012.
Cf. A049826.
Cf. A130130 (central terms).

a051010 n k = snd $ until ((== 0) . snd . fst)
                    (\((x, y), i) -> ((y, mod x y), i + 1)) ((n, k), 0)
a051010_row n = map (a051010 n) [0..n-1]
a051010_tabl = map a051010_row [1..]
-- Reinhard Zumkeller, Jun 27 2013

t[m_, n_] := For[r[-1]=m; r[0]=n; k=1, True, k++, r[k] = Mod[r[k-2], r[k-1]]; If[r[k] == 0, Return[k-1]]]; Table[ t[m, n] , {n, 1, 14}, {m, 0, n-1}] // Flatten (* Jean-François Alcover, Oct 25 2012 *)

A051012 Denominator of average of number of steps in Euclidean algorithm for all gcd(m,n) with 0 <= m < n.

Original entry on oeis.org

1, 2, 1, 1, 5, 6, 7, 4, 9, 10, 11, 3, 13, 14, 15, 8, 17, 18, 19, 5, 21, 2, 23, 4, 25, 26, 9, 7, 29, 30, 31, 16, 11, 34, 35, 9, 37, 38, 13, 4, 41, 42, 43, 1, 15, 46, 47, 8, 49, 50, 51, 13, 53, 54, 55, 28, 19, 58, 59, 15, 61, 62, 63, 32, 65, 6, 67, 17, 69, 70, 71, 36, 73, 74, 75

Offset: 1

Eric W. Weisstein

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000
Eric Weisstein's World of Mathematics, Euclidean Algorithm.

Cf. A034883, A051010, A051011 (numerators).

import Data.Ratio ((%), denominator)
a051012 n = denominator $ (sum $ a051010_row n) % n
-- Reinhard Zumkeller, Jun 27 2013

t[m_, n_] := For[r[-1]=m; r[0]=n; k=1, True, k++, r[k] = Mod[r[k-2], r[k-1]]; If[r[k] == 0, Return[k-1]]]; a[n_] := Denominator[Sum[t[m, n], {m, 0, n}]/n]; Array[a, 100] (* Amiram Eldar, Apr 22 2022 after Jean-François Alcover at A051010 *)

cp's OEIS Frontend

A051010 Triangle T(m,n) giving of number of steps in the Euclidean algorithm for gcd(m,n) with 0<=m

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