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A029987 Squares which are palindromes in base 4. 11
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..26.

Patrick De Geest, Palindromic Squares

EXAMPLE

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.

MATHEMATICA

palindromicQ[n_, b_:10] := TrueQ[IntegerDigits[n, b] == Reverse[IntegerDigits[n, b]]]; Select[Range[1000]^2, palindromicQ[#, 4] &] (* Alonso del Arte, Mar 04 2017 *)

PROG

(PARI) lista(nn) = for (n=0, nn, d = digits(n^2, 4); if (Vecrev(d) == d, print1(n^2, ", "))); \\ Michel Marcus, Mar 05 2017

CROSSREFS

Cf. A029986.

Sequence in context: A160084 A265967 A225873 * A017582 A210430 A158990

Adjacent sequences:  A029984 A029985 A029986 * A029988 A029989 A029990

KEYWORD

nonn,base

AUTHOR

Patrick De Geest

STATUS

approved

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Last modified August 22 10:37 EDT 2017. Contains 290946 sequences.