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A166537 Integers whose binary digits "1" define, if sorted into a quadrant shape whose right angle lies in a Go board corner, same colored Go stones that surely live all, but not if any stone is omitted 1
430, 441, 2262, 2534, 2546, 4494, 4518, 6493, 6494, 6510, 6521, 6522, 6598, 6627, 8982, 9102, 9116, 11206, 11218, 11220, 12974, 12979, 12982, 12985, 12988, 13190, 13197, 14969, 14974, 15078, 15092, 15182, 15194, 68758, 68764, 69030, 69042 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..37.

Sensei's Library, Corner shapes

EXAMPLE

2534 has the binary expansion 100111100110. Sorting into a quadrant shape (like in A165197, the least-significant digit into the corner) leads to:

0110

101

01

11

0

If the "0" top left is in a Go board corner and only the 7 digits "1" are Go stones of the same color, then all these 7 stones surely live, no matter where stones or chains of the other color with freedom(s) are. Removal of any of the 7 "1"-stones removes this sureness (for the remaining stones).

CROSSREFS

Sequence in context: A227597 A321976 A147694 * A165058 A165062 A203545

Adjacent sequences:  A166534 A166535 A166536 * A166538 A166539 A166540

KEYWORD

nonn,base

AUTHOR

Leonhard Kreissig, Oct 16 2009

STATUS

approved

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Last modified October 17 17:21 EDT 2021. Contains 348065 sequences. (Running on oeis4.)