The OEIS is looking to hire part-time people to help edit core sequences, upload scanned documents, process citations, fix broken links, etc. - Neil Sloane, email@example.com
Polyominoes with n cells and at least one line of reflection symmetry. - Joshua Zucker, Mar 08 2008
Table of n, a(n) for n=1..22.
Cf. A000105, A006746.
Sequence in context: A135452 A077027 A030436 * A180272 A061551 A026034
Adjacent sequences: A030224 A030225 A030226 * A030228 A030229 A030230
David W. Wilson