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URL: https://oeis.org/A061230

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A061230
Numbers k such that k + the reversal of k is a square.
7
0, 2, 8, 29, 38, 47, 56, 65, 74, 83, 92, 110, 143, 164, 198, 242, 263, 297, 341, 362, 396, 440, 461, 495, 560, 594, 693, 792, 891, 990, 10100, 10148, 10340, 10395, 10403, 10683, 10908, 10980, 11138, 11330, 11385, 11673, 11970, 12128, 12320, 12375
OFFSET
1,2
LINKS
Michael S. Branicky, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Paolo P. Lava)
EXAMPLE
8 is a term as 8 + 8 = 16 = 4^2.
56 is a term as 56 + 65 = 121 = 11^2.
MAPLE
digrev:= proc(n) local L, i;
L:= convert(n, base, 10);
add(L[-i]*10^(i-1), i=1..nops(L))
end proc:
select(t -> issqr(t+digrev(t)), [$0..20000]); # Robert Israel, May 04 2015
MATHEMATICA
Select[Range[0, 15000], IntegerQ[Sqrt[#+FromDigits[Reverse[ IntegerDigits[#]]]]]&] (* Harvey P. Dale, Apr 18 2011 *)
PROG
(PARI) isok(n) = issquare(n + fromdigits(Vecrev(digits(n)))); \\ Michel Marcus, Aug 04 2019
(Python)
from math import isqrt
def issquare(n): return isqrt(n)**2 == n
def ok(n): return issquare(n + int(str(n)[::-1]))
print([k for k in range(12376) if ok(k)]) # Michael S. Branicky, Dec 09 2022
CROSSREFS
Cf. A359011 (for squares).
Sequence in context: A330211 A216785 A261559 * A241627 A293169 A306847
KEYWORD
nonn,base
AUTHOR
Amarnath Murthy, Apr 23 2001
EXTENSIONS
Corrected and extended by Patrick De Geest, May 28 2001
Edited by N. J. A. Sloane, Jul 24 2009
STATUS
approved