A178461 - OEIS

A178461

Integers whose binary digits "1" define, iff these integers are not decreased by one, Arimaa pieces of both colors so that an enemy piece can be removable in all possible color combinations in one turn (= 4 steps) if sorted into a quadrant shape whose right angle lies in an Arimaa board corner.

10, 18, 20, 22, 26, 30, 36, 52, 54, 62, 72, 74, 90, 94, 126, 129, 136, 144, 148, 152, 154, 156, 158, 160, 168, 180, 188, 190, 192, 200, 208, 212, 216, 218, 220, 222, 224, 232, 244, 252, 254, 257, 264, 272, 278, 288, 296, 304, 306, 308, 310, 314, 318, 328, 346, 350, 360, 378, 382, 384, 392, 400, 408, 414, 416, 424, 432, 436, 440, 442, 444, 446, 448, 456

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OFFSET

1,1

LINKS

Table of n, a(n) for n=1..74.

Academic Papers and Presentations

EXAMPLE

168 has the binary expansion 10101000. Sorting into a quadrant shape (like in A165197, A166537, the least-significant digit into the corner) with a "T" on position (3,3) leads to:

001

11T

Either the left piece pushes to right or the upper piece comes down and pushes in a right angle. So in both possible color combinations an enemy piece can be brought into the trap field "T". The following integers till 174 bring for possible removabilities sufficiently movable pieces into the 4 vacant corner fields.

CROSSREFS

Sequence in context: A004752 A087141 A349090 * A043724 A043571 A043732

Adjacent sequences: A178458 A178459 A178460 * A178462 A178463 A178464

KEYWORD

nonn,base,uned

AUTHOR

Leonhard Kreissig, Dec 24 2010

STATUS

approved