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A092394
Largest gcd of two distinct numbers on row n of Pascal's triangle.
1
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
2,3
LINKS
EXAMPLE
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.
MATHEMATICA
Max /@ (GCD[#1, #2] & @@@ Subsets[#, {2}] & /@ Table[Binomial[n, k], {n, 2, 36}, {k, 0, Floor[n/2]}]) (* Michael De Vlieger, Feb 26 2016 *)
PROG
(PARI) 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
CROSSREFS
Sequence in context: A165917 A165898 A194531 * A027438 A334388 A204237
KEYWORD
easy,nonn
AUTHOR
David Wasserman, Mar 21 2004
STATUS
approved