A015708 Numbers k such that k | (phi(k) * sigma(k)) but (phi(k) + sigma(k))/k does not increase.

1, 84, 120, 162, 234, 252, 270, 486, 540, 588, 648, 672, 819, 936, 1350, 1458, 1536, 1550, 1638, 1764, 1782, 1800, 1872, 1920, 2268, 2325, 3000, 3042, 3240, 3276, 3402, 3564, 3724, 3780, 4116, 4374, 4464, 4650, 4680, 4704, 5292, 5376

Offset

1,2

Links

Table of n, a(n) for n=1..42.

Richard K. Guy, Divisors and desires, Amer. Math. Monthly, 104 (1997), 359-360.

Crossrefs

Sequence in context: A316834 A227734 A192322 * A114822 A099637 A274348

Adjacent sequences: A015705 A015706 A015707 * A015709 A015710 A015711

Keyword

nonn

Author

Robert G. Wilson v

Status

approved