A028559 - OEIS

%I #25 May 05 2024 08:55:57

%S 0,6,66,414,696,41814,42224,666666,4282824,4754574,4881884,416343614,

%T 630939036,4159669514,6817557186,42877777824,4163250523614,

%U 4783601063874,4986733376894,47431877813474,6333914444193336,44653247574235644,62141509790514126

%N Palindromes of the form k*(k+5).

%H Lior Manor, <a href="/A028559/b028559.txt">Table of n, a(n) for n = 1..33</a> (terms 1..27 from Michael S. Branicky)

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

%F a(n) = A028558(n) * (A028558(n) + 5). - _Michael S. Branicky_, Jan 30 2022

%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+5)):

%o             yield k*(k+5)

%o print(list(islice(agen(), 20))) # _Michael S. Branicky_, Jan 30 2022

%Y Cf. A028557, A028558.

%K nonn,base

%O 1,2

%A _Patrick De Geest_

%E a(21) and beyond from _Michael S. Branicky_, Jan 30 2022