

A038388


Let f(n) be the smallest number such that the arithmetic mean (A) and geometric mean (G) of n and f(n) are both integers; sequence gives G values.


2



1, 2, 3, 4, 5, 6, 7, 4, 3, 10, 11, 12, 13, 14, 15, 8, 17, 6, 19, 20, 21, 22, 23, 12, 5, 26, 9, 28, 29, 30, 31, 8, 33, 34, 35, 12, 37, 38, 39, 20, 41, 42, 43, 44, 15, 46, 47, 24, 7, 10, 51, 52, 53, 18, 55, 28, 57, 58, 59, 60, 61, 62, 21, 16, 65, 66, 67, 68, 69, 70, 71, 12, 73, 74, 15
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..75.


FORMULA

Multiplicative with a(p^e) = p^((e+1)/2) if e is odd, 2^(e/2+1) if p=2 and e is even, p^(e/2) if p>2 and e is even.  Vladeta Jovovic, May 15 2003


MATHEMATICA

Table[k = 1; While[Nand @@ IntegerQ /@ {(n + k)/2, g = Sqrt[n*k]}, k++]; g, {n, 75}] (* Jayanta Basu, Jul 14 2013 *)


CROSSREFS

Cf. A038387, A038389.
Cf. A053626, A053627.
Sequence in context: A278059 A115871 A138221 * A272573 A319999 A083501
Adjacent sequences: A038385 A038386 A038387 * A038389 A038390 A038391


KEYWORD

nonn,mult


AUTHOR

N. J. A. Sloane.


EXTENSIONS

More terms from Vladeta Jovovic, May 15 2003


STATUS

approved



