login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A029733
Numbers k such that k^2 is palindromic in base 16.
12
0, 1, 2, 3, 17, 34, 257, 273, 289, 305, 319, 514, 530, 546, 773, 1377, 4097, 4369, 4641, 8194, 8254, 8466, 8734, 9046, 51629, 65537, 65793, 66049, 66305, 69649, 69905, 70161, 70417, 73505, 73761, 74017, 74273, 76879, 92327, 131074
OFFSET
1,3
LINKS
MATHEMATICA
n2palQ[n_]:=Module[{id=IntegerDigits[n^2, 16]}, id==Reverse[id]]; Select[ Range[ 0, 150000], n2palQ] (* Harvey P. Dale, Mar 31 2018 *)
PROG
(Python)
from itertools import count, islice
def A029733_gen(): # generator of terms
return filter(lambda k: (s:=hex(k**2)[2:])[:(t:=(len(s)+1)//2)]==s[:-t-1:-1], count(0))
A029733_list = list(islice(A029733_gen(), 20)) # Chai Wah Wu, Jun 23 2022
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), A030073 (b=15), this sequence (b=16), A118651 (b=17).
Sequence in context: A193051 A217688 A263570 * A153686 A042137 A067976
KEYWORD
nonn,base
STATUS
approved