A091963 -id:A091963 - cp's OEIS frontend

A092394 Largest gcd of two distinct numbers on row n of Pascal's triangle.

1, 1, 2, 5, 5, 7, 28, 42, 42, 165, 132, 429, 1001, 1001, 1430, 6188, 4862, 25194, 41990, 58786, 58786, 245157, 653752, 742900, 1931540, 4345965, 2674440, 17298645, 9694845, 29464725, 94287120, 129644790, 927983760, 811985790, 477638700

Offset: 2

David Wasserman, Mar 21 2004

			For n = 6, the numbers on the row are 1, 6, 15 and 20 and the gcd's of pairs of these are 1, 3, 2 and 5. So a(6) = 5.

Michael De Vlieger, Table of n, a(n) for n = 2..1000

Cf. A007318, A091963.

Max /@ (GCD[#1, #2] & @@@ Subsets[#, {2}] & /@ Table[Binomial[n, k], {n, 2, 36}, {k, 0, Floor[n/2]}]) (* Michael De Vlieger, Feb 26 2016 *)

mg(n) = {my(m = 0, v = vecsort(vector(n+1, k, k--; binomial(n,k)),,8));for (k=2, #v, for (j=1, k-1, m = max(m, gcd(v[k], v[j])););); m;} \\ Michel Marcus, Feb 26 2016

A092461 Let S_n be the set {n!/(i!j!k!) | i, j, k > 0, i+j+k = n} (i.e., trinomial coefficients that involve all three monomials). Then a(n) is the smallest gcd of any three members of S_n.

Original entry on oeis.org

6, 12, 10, 30, 7, 28, 6, 30, 11, 66, 13, 91, 6, 12, 34, 102, 19, 38, 12, 22, 23, 46, 15, 65, 6, 12, 29, 435, 62, 124, 6, 34, 10, 36, 37, 703, 6, 24, 41, 82, 86, 43, 20, 46, 47, 94, 21, 70, 6, 12, 53, 159, 10, 35, 21, 58, 59, 177, 61, 1891, 14, 28, 10, 30, 67, 134, 12, 14, 142, 142

Offset: 3

David Wasserman, Mar 25 2004

Are there any 1's in this sequence?

			S_7 = {42, 105, 140, 210}, gcd(42, 105, 140) = 7, gcd(42, 105, 210) = 21, gcd(42, 140, 210) = 14, gcd(105, 140, 210) = 35. So a(7) is the smallest of these, 7.

Cf. A046816, A091963.

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A092394 Largest gcd of two distinct numbers on row n of Pascal's triangle.

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A092461 Let S_n be the set {n!/(i!j!k!) | i, j, k > 0, i+j+k = n} (i.e., trinomial coefficients that involve all three monomials). Then a(n) is the smallest gcd of any three members of S_n.

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cp's OEIS Frontend

A092394 Largest gcd of two distinct numbers on row n of Pascal's triangle.

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Author

Keywords

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Mathematica

PARI

A092461 Let S_n be the set {n!/(i!*j!*k!) | i, j, k > 0, i+j+k = n} (i.e., trinomial coefficients that involve all three monomials). Then a(n) is the smallest gcd of any three members of S_n.

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A092461 Let S_n be the set {n!/(i!j!k!) | i, j, k > 0, i+j+k = n} (i.e., trinomial coefficients that involve all three monomials). Then a(n) is the smallest gcd of any three members of S_n.