A029986 - OEIS

A029986

Numbers k such that k^2 is palindromic in base 4.

0, 1, 5, 17, 21, 65, 71, 83, 257, 273, 281, 317, 1025, 1055, 4097, 4161, 4193, 4401, 5157, 5179, 5221, 16385, 16511, 16865, 17239, 65537, 65793, 65921, 66753, 68695, 69521, 69777, 80739, 82053, 82171, 82309, 82885, 83301, 262145

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,3

LINKS

Seiichi Manyama, Table of n, a(n) for n = 1..100

Patrick De Geest, Palindromic Squares

MATHEMATICA

Select[Range[0, 300000], IntegerDigits[#^2, 4]==Reverse[ IntegerDigits[ #^2, 4]]&] (* Harvey P. Dale, Dec 01 2015 *)

PROG

(PARI) isok(k) = my(d=digits(k^2, 4)); d == Vecrev(d); \\ Michel Marcus, Jul 04 2021

CROSSREFS

Cf. A007090, A014192.

Numbers k such that k^2 is palindromic in base b: A003166 (b=2), A029984 (b=3), this sequence (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), A030073 (b=15), A029733 (b=16), A118651 (b=17).

Sequence in context: A191143 A032376 A145818 * A076275 A316307 A317262

Adjacent sequences: A029983 A029984 A029985 * A029987 A029988 A029989

KEYWORD

nonn,base

AUTHOR

Patrick De Geest

STATUS

approved