cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Previous Showing 11-14 of 14 results.

A030072 Numbers k such that k^2 is palindromic in base 14.

Original entry on oeis.org

0, 1, 2, 3, 15, 24, 30, 47, 165, 197, 211, 225, 239, 394, 408, 422, 2190, 2445, 2745, 2955, 3165, 5490, 5700, 8565, 38417, 38613, 38809, 39005, 41175, 41371, 41567, 41763, 43737, 43933, 44129, 48159, 55962, 76834, 77030, 77226, 79592, 79788
Offset: 1

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Keywords

Crossrefs

Numbers k such that k^2 is palindromic in base b: A003166 (b=2), A029984 (b=3), A029986 (b=4), A029988 (b=5), A029990 (b=6), A029992 (b=7), A029805 (b=8), A029994 (b=9), A002778 (b=10), A029996 (b=11), A029737 (b=12), A029998 (b=13), this sequence (b=14), A030073 (b=15), A029733 (b=16), A118651 (b=17).

Programs

  • Mathematica
    pal14Q[n_]:=Module[{idn14=IntegerDigits[n^2,14]},idn14==Reverse[idn14]]; Select[Range[0,80000],pal14Q] (* Harvey P. Dale, Mar 09 2012 *)

A030073 Numbers k such that k^2 is palindromic in base 15.

Original entry on oeis.org

0, 1, 2, 3, 4, 8, 12, 16, 19, 32, 39, 64, 76, 128, 144, 226, 241, 256, 271, 311, 452, 467, 478, 482, 576, 715, 904, 964, 1024, 1748, 1808, 1868, 2304, 2652, 2860, 3376, 3401, 3616, 3856, 4639, 6752, 6992, 7172, 8649, 10715, 13504, 13604
Offset: 1

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Author

Keywords

Crossrefs

Numbers k such that k^2 is palindromic in base b: A003166 (b=2), A029984 (b=3), A029986 (b=4), A029988 (b=5), A029990 (b=6), A029992 (b=7), A029805 (b=8), A029994 (b=9), A002778 (b=10), A029996 (b=11), A029737 (b=12), A029998 (b=13), A030072 (b=14), this sequence (b=15), A029733 (b=16), A118651 (b=17).

Programs

  • Mathematica
    p15Q[n_]:=Module[{id15=IntegerDigits[n^2,15]},id15==Reverse[id15]]; Select[ Range[0,14000],p15Q] (* Harvey P. Dale, Jun 03 2020 *)

A263610 Palindromes in base 4 which are also squares.

Original entry on oeis.org

0, 1, 121, 10201, 12321, 1002001, 1032301, 1223221, 100020001, 102030201, 103101301, 120202021, 10000200001, 10033233001, 1000002000001, 1002003002001, 1003010103001, 1021320231201, 1211130311121, 1212110112121, 1213332333121, 100000020000001, 100033323330001, 100331000133001
Offset: 1

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Author

N. J. A. Sloane, Oct 22 2015

Keywords

Crossrefs

A263609 Base-4 numbers whose square is a palindrome in base 4.

Original entry on oeis.org

0, 1, 11, 101, 111, 1001, 1013, 1103, 10001, 10101, 10121, 10331, 100001, 100133, 1000001, 1001001, 1001201, 1010301, 1100211, 1100323, 1101211, 10000001, 10001333, 10013201, 10031113, 100000001, 100010001, 100012001, 100103001, 100301113, 100332101, 101002101, 103231203, 110002011
Offset: 1

Views

Author

N. J. A. Sloane, Oct 22 2015

Keywords

Examples

			From _Mattew Bondar_, Mar 12 2021: (Start)
111_4 = 21_10, 21^2 = 441, 441_10 = 12321_4 (palindrome).
1013_4 = 71_10, 71^2 = 5041, 5041_10 = 1032301_4 (palindrome). (End)
		

Crossrefs

Programs

  • Mathematica
    FromDigits /@ IntegerDigits[Select[Range[0, 2^17], PalindromeQ@ IntegerDigits[#^2, 4] &], 4] (* Michael De Vlieger, Mar 13 2021 *)
  • Python
    def decimal_to_quaternary(n):
        if n == 0:
            return '0'
        b = ''
        while n > 0:
            b = str(n % 4) + b
            n = n // 4
        return b
    x = 0
    counter = 0
    while True:
        y = decimal_to_quaternary(x ** 2)
        if y == y[::-1]:
            print(int(decimal_to_quaternary(x)))
            counter += 1
        x += 1  # Mattew Bondar, Mar 10 2021
Previous Showing 11-14 of 14 results.