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A232501
Numbers k such that distances from k to three nearest squares are three triangular numbers.
2
1, 10, 15, 19, 26, 197, 253, 325, 631, 1090, 1522, 2395, 3601, 4434, 4625, 6571, 9026, 11026, 11116, 14631, 15454, 19045, 22501, 35722, 38431, 41210, 53036, 61505, 65521, 66239, 69697, 69949, 70291, 85384, 99226, 110890, 152101, 152803, 160021, 168101, 181801, 189631
OFFSET
1,2
LINKS
PROG
(Haskell)
import Data.List (sort)
a232501 n = a232501_list !! (n-1)
a232501_list = filter f [1..] where
f x = all ((== 1) . a010054) $ init $ sort $
map (abs . (x -) . (^ 2) . (+ (a000196 x))) [-1..2]
-- Reinhard Zumkeller, Mar 16 2014
CROSSREFS
Cf. A232608 (terms that are triangular numbers).
Sequence in context: A135363 A118717 A181529 * A138593 A362010 A004259
KEYWORD
nonn
AUTHOR
Alex Ratushnyak, Feb 23 2014
STATUS
approved