A151519 Number of 1-sided polytans (polyaboloes) with n cells.

1, 4, 6, 22, 56, 198, 624, 2182, 7448, 26319, 92826, 332181, 1192845, 4315845, 15678200, 57227380, 209623109, 770516966, 2840466846, 10499678185, 38905008340, 144475534207

Offset

1,2

Links

Table of n, a(n) for n=1..22.

Ed Pegg, Jr., Illustrations of polyforms.

Eric Weisstein's World of Mathematics, Polyabolo.

Formula

a(n) = A353978(n)/4 if n is odd. - Pontus von Brömssen, Nov 26 2025

Crossrefs

Cf. A006074 (free), A353978 (fixed).

Sequence in context: A083157 A192154 A289385 * A061595 A062940 A061596

Adjacent sequences: A151516 A151517 A151518 * A151520 A151521 A151522

Keyword

nonn,hard,more

Author

Ed Pegg Jr, May 13 2009

Extensions

a(13)-a(14) from George Sicherman, Sep 27 2012

a(15) from George Sicherman, Aug 06 2013

a(15) corrected and a(16)-a(20) from John Mason, Jan 07 2022

a(21)-a(22) from Aaron N. Siegel, Jun 07 2022

Status

approved