OFFSET
1,2
COMMENTS
Is this a permutation of the positive integers?
LINKS
Ivan Neretin, Table of n, a(n) for n = 1..1000
EXAMPLE
a(1)+a(2)+a(3)+a(4)+a(5)+a(6) = 1+2+3+6+4+8 = 24. a(1)*a(2)*a(3)*a(4)*a(5)*a(6) = 1152. And 24 divides 1152. Had a(6) been any of the positive integers which are < 8 and do not occur earlier in the sequence (i.e., had it been 5 or 7), then the sum of the first 6 terms of the sequence would not have divided the product of the first 6 terms.
MATHEMATICA
f[l_List] := Block[{k = 1, s = Plus @@ l, p = Times @@ l}, While[MemberQ[l, k] || Mod[k*p, k + s] > 0, k++ ]; Append[l, k]]; Nest[f, {1, 2}, 75] (* Ray Chandler, Jan 22 2007 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Jan 18 2007
EXTENSIONS
Extended by Ray Chandler, Jan 22 2007
STATUS
approved