A097014 Smallest x such that sigma(x) mod 210 = n.

104, 1, 211, 2, 3, 8311689, 5, 4, 7, 3698, 399, 130321, 6, 9, 13, 8, 1477, 2458624, 10, 725904, 19, 676, 6751, 18766224, 14, 52707600, 489, 24649, 12, 220433409, 29, 16, 21, 1250, 2779, 3694084, 22, 5184, 37, 18, 27, 1382976, 20, 729, 43, 128, 217

Offset

0,1

Comments

Compare with A084303 and A097013.

Row 210 of A074625 (apart from different ordering). - Michel Marcus, Dec 19 2013

Links

Michel Marcus, Table of n, a(n) for n = 0..209

Example

Several numbers belonging to odd residues are either large squares or twice-squares.
E.g.: r = n = 209: a(209) = 36324729 = 6027^2, sigma(6027^2) = 210*172974 + 209.
Full set is easily available running through squares or twice squares.

Crossrefs

Cf. A000203, A084301, A084303, A097011, A097012, A097013, A097015.

Sequence in context: A262273 A088584 A238490 * A106297 A090849 A091025

Adjacent sequences: A097011 A097012 A097013 * A097015 A097016 A097017

Keyword

fini,nonn

Author

Labos Elemer, Aug 19 2004

Status

approved