|
%I #15 Aug 11 2024 14:41:29
%S 0,4,88,868,4554,8008,45154,89698,452254,4526254,8996998,830333038,
%T 862626268,899969998,4058008504,45032023054,45229592254,89999699998,
%U 405485584504,4503764673054,8187727277818,8999996999998,89178266287198,455467838764554,833066101660338
%N Palindromes of form n(n+3).
%C Also: Palindromes that are the sum of consecutive initial even composites. Sequence 4 + 6 + 8 + 10 + 12 + 14 + ... + z = n. For values of z see A058851. (Comment added by author 12/2000).
%C 9*10^(2n)-3*10^n-2 for n >= 0 are terms. For n > 1, the first (and last digit) of a(n) is either 4 or 8. - _Chai Wah Wu_, Feb 20 2021
%H Chai Wah Wu, <a href="/A028554/b028554.txt">Table of n, a(n) for n = 1..40</a>
%H P. De Geest, <a href="https://www.worldofnumbers.com/consemor.htm">Palindromic Quasipronics</a>
%H P. De Geest, <a href="https://www.worldofnumbers.com/firstpal.htm#sfn5">Palindromic Sums 2</a>
%o (Python)
%o n, m, A028554_list = 4, 0, []
%o while n < 10**12:
%o s = str(m)
%o if s == s[::-1]:
%o A028554_list.append(m)
%o m += n
%o n += 2 # _Chai Wah Wu_, Feb 20 2021
%Y Cf. A028553, A058851.
%K nonn,base
%O 1,2
%A _Patrick De Geest_
%E More terms from _Chai Wah Wu_, Feb 20 2021
|
