A389190 Number of fixed polyiamonds of area n with holes.

0, 0, 0, 0, 0, 0, 0, 0, 6, 48, 270, 1268, 5292, 20439, 74814, 263355, 901008, 3017115, 9937114, 32304714, 103923708, 331464966, 1049720568, 3304628530, 10351016262, 32283173154, 100314652764, 310715722757, 959736443148, 2957200232043, 9092350392378, 27902684897727, 85483519917846

Offset

1,9

Links

Table of n, a(n) for n=1..33.

Formula

a(n) = A001420(n) - A341630(n).

Crossrefs

Cf. A001420, A070764, A341630, A389191.

Sequence in context: A056289 A056284 A366622 * A293967 A246587 A340309

Adjacent sequences: A389187 A389188 A389189 * A389191 A389192 A389193

Keyword

nonn

Author

John Mason, Sep 25 2025

Status

approved