OFFSET
1,1
COMMENTS
See A341160 for an image of the square spiral tiling which shows the uncovered numbers in black.
EXAMPLE
a(1) = 6 and a(2) = 19 as the first, third, fourth, and seventh square of A341160 cover the numbers (1), (5,18), (7,20), (40) respectively which leaves a gap containing numbers 6 and 19 which cannot be covered by any subsequence square.
CROSSREFS
KEYWORD
nonn
AUTHOR
Scott R. Shannon, Feb 09 2021
STATUS
approved