A084293 a(n) = 2n + A054905(n).

436, 305635361, 110, 35, 195566, 77, 26, 55, 38, 76, 938, 104, 212308, 85, 74, 106677, 86, 161

Offset

1,1

Comments

The sequence begins 436, 305635361, 110, 35, 195566, 77, 26, 55, 38, 76, 938, 104, 212308, 85, 74, 106677, 86, 161, ?, 91, 87, 92, 122, 111, 1585396, 145, 94, 76627, 10283, 159, 772, 133, 122, 412, 194, 142, 964, 205, 374, 925, 6725, 209, ?, 1015, 178, ?, ?, 206, 146, ?, ..., where the other missing terms (designated by "?") are unknown, if they exist (see also A206768).

Links

Table of n, a(n) for n=1..18.

Formula

Composite x satisfying sigma(x-2n) = sigma(x) - 2n.

Example

To terms of A054905, where sigma(x+2n)=sigma(x)+2n replacing x+2n=y,x=y-2n, we get sigma(y)-2n=sigma(y-2n);
For several analogous sequences, the corresponding "mirror-solutions" can be easily constructed. See: e.g. A015913-A015918; A050507, A054799, A054903-A054906; A054982-A054987; A059118; A055009, A055458, A063500, etc.

Crossrefs

Cf. A054905.

Sequence in context: A243233 A216988 A190828 * A237939 A088893 A043447

Adjacent sequences: A084290 A084291 A084292 * A084294 A084295 A084296

Keyword

nonn,more

Author

Labos Elemer, May 26 2003

Status

approved