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A350918
Numbers k = x.y which when split into two parts x and y of equal length, added and squared result in the same number k, '.' means concatenation, and the second part y starts with 0.
1
9801, 998001, 99980001, 9048004641, 9999800001, 923594037444, 989444005264, 999998000001, 7901234409876544, 8434234407495744, 8934133805179209, 9999999800000001, 999999998000000001, 79012345680987654321, 82644628100826446281, 83407877440792003584, 87138706300620940900
OFFSET
1,1
COMMENTS
Problem proposed on French site Diophante (see link).
EXAMPLE
(998+001)^2 = 999^2 = 998001, as x = 998 and y = 001 starts with 0, 998001 is a term.
(30+25)^2 = 55^2 = 3025, here x = 30 but y = 25 does not start with 0, hence 3025 is not a term.
CROSSREFS
Equals A238237 \ A350870.
A059988 \ {0, 81} is a subsequence.
Sequence in context: A222814 A156735 A227489 * A113937 A036353 A174769
KEYWORD
nonn,base
AUTHOR
Bernard Schott, Jan 22 2022
STATUS
approved