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A029987
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Squares which are palindromes in base 4.
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14
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0, 1, 25, 289, 441, 4225, 5041, 6889, 66049, 74529, 78961, 100489, 1050625, 1113025, 16785409, 17313921, 17581249, 19368801, 26594649, 26822041, 27258841, 268468225, 272613121, 284428225, 297183121, 4295098369
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OFFSET
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1,3
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LINKS
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EXAMPLE
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5^2 = 25 in base 4 is 121, which is a palindrome, hence 25 is in the sequence.
6^2 = 36 in base 4 is 210, which is not a palindrome, so 36 is not in the sequence.
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MATHEMATICA
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palindromicQ[n_, b_:10] := TrueQ[IntegerDigits[n, b] == Reverse[IntegerDigits[n, b]]]; Select[Range[1000]^2, palindromicQ[#, 4] &] (* Alonso del Arte, Mar 04 2017 *)
Select[Range[0, 70000]^2, IntegerDigits[#, 4]==Reverse[IntegerDigits[#, 4]]&] (* Harvey P. Dale, May 07 2022 *)
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PROG
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(PARI) lista(nn) = for (n=0, nn, d = digits(n^2, 4); if (Vecrev(d) == d, print1(n^2, ", "))); \\ Michel Marcus, Mar 05 2017
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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STATUS
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approved
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