OFFSET
1,2
COMMENTS
It is the average of A038387 with n, both of which are multiplicative. - Christian G. Bower, May 16 2005
However, this sequence is not multiplicative. The first nonmultiplicative term is a(72) = 37 which is not multiplicative since a(8)*a(9) = 5*5 = 25. - Andrew Howroyd, Feb 12 2018
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..1000
MATHEMATICA
Table[k = 1; While[Nand @@ IntegerQ /@ {a = (n + k)/2, Sqrt[n*k]}, k++]; a, {n, 78}] (* Jayanta Basu, Jul 14 2013 *)
PROG
(PARI) a(n)={for(k=1, n, if((n+k)%2==0 && issquare(n*k), return((n+k)/2)))} \\ Andrew Howroyd, Feb 12 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved