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A028567 Numbers k such that k*(k+8) is a palindrome. 2

%I #23 Jan 25 2022 08:30:48

%S 0,1,3,66,88,91,173,216,225,284,294,696,707,924,2235,2828,6996,9394,

%T 28314,30031,57489,69996,93844,188583,228175,241097,283778,298144,

%U 597883,699996,896478,1934063,2281817,6999996,7243225,17646619,17869169,19782199,23352327

%N Numbers k such that k*(k+8) is a palindrome.

%C For i >= 0, 69^i6 is a term with corresponding palindrome 48(99)^{2*i}84, where ^ is repeated concatenation. - _Michael S. Branicky_, Jan 24 2022

%H Michael S. Branicky, <a href="/A028567/b028567.txt">Table of n, a(n) for n = 1..58</a>

%H Patrick De Geest, <a href="http://www.worldofnumbers.com/consemor.htm">Palindromic Quasipronics of the form n(n+x)</a>

%H Erich Friedman, <a href="https://erich-friedman.github.io/numbers.html">What's Special About This Number?</a> (See entries 696, 2235, 2828, 6996, 9394.)

%t Select[Range[0,8*10^6],PalindromeQ[#(#+8)]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, May 28 2017 *)

%o (Python)

%o from itertools import count, islice

%o def ispal(n): s = str(n); return s == s[::-1]

%o def agen():

%o for k in count(0):

%o if ispal(k*(k+8)):

%o yield k

%o print(list(islice(agen(), 35))) # _Michael S. Branicky_, Jan 24 2022

%K nonn,base

%O 1,3

%A _Patrick De Geest_

%E a(36) and beyond from _Michael S. Branicky_, Jan 24 2022

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Last modified April 24 19:06 EDT 2024. Contains 371962 sequences. (Running on oeis4.)