OFFSET
1,3
LINKS
Rémy Sigrist, Table of n, a(n) for n = 1..10000
Rémy Sigrist, C program for A127431
EXAMPLE
(1+11) is a multiple of a(1)=1; (2+11) is a multiple of a(2)=1; (3+11) is a multiple of a(3)=2; and (9+11) is a multiple of a(9)=5. These four cases are the only cases where (k+n) is divisible by a(k), for 1<=k<=10. So a(11) = 4.
MATHEMATICA
f[l_List] := Block[{n = Length[l] + 1}, Append[l, Count[Table[Mod[k + n, l[[k]]], {k, n - 1}], 0]]]; Nest[f, {1}, 86] (* Ray Chandler, Jan 22 2007 *)
PROG
(C) See Links section.
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Leroy Quet, Jan 14 2007
EXTENSIONS
Extended by Ray Chandler, Jan 22 2007
STATUS
approved