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A033294
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Squares which when written backwards remain square (final 0's excluded).
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4
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1, 4, 9, 121, 144, 169, 441, 484, 676, 961, 1089, 9801, 10201, 10404, 10609, 12321, 12544, 12769, 14641, 14884, 40401, 40804, 44521, 44944, 48841, 69696, 90601, 94249, 96721, 698896, 1002001, 1004004, 1006009, 1022121, 1024144, 1026169
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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LINKS
| Reinhard Zumkeller, Table of n, a(n) for n = 1..1000
Index entry for sequences related to reversing digits of squares
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EXAMPLE
| 144 = 12 * 12 is a term because 441 = 21 * 21
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PROG
| (Haskell)
a033294 n = a033294_list !! (n-1)
a033294_list = filter chi a000290_list where
chi m = m `mod` 10 > 0 && head ds `elem` [1, 4, 5, 6, 9] &&
a010052 (foldl (\v d -> 10 * v + d) 0 ds) == 1 where
ds = unfoldr
(\x -> if x == 0 then Nothing else Just $ swap $ divMod x 10) m
-- Reinhard Zumkeller, Jan 19 2012
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CROSSREFS
| Cf. A007488, A007500.
Sequence in context: A117680 A042649 A042381 * A156317 A115676 A115667
Adjacent sequences: A033291 A033292 A033293 * A033295 A033296 A033297
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KEYWORD
| base,nonn
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AUTHOR
| Jeff Burch (jmburch(AT)osprey.smcm.edu)
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EXTENSIONS
| More terms from Erich Friedman (erich.friedman(AT)stetson.edu).
Initial 0 removed and offset changed by Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jan 19 2012
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