cp's OEIS Frontend

A099052 All palindromes of length greater than 1 in the decimal expansion of e, ordered by the ending position of the palindrome. Multiple terms ending at the same position are ordered by the starting position of the palindrome.

%I A099052 #12 Jun 29 2021 02:33:30
%S A099052 828,18281,818,28182,8281828,828,353,747,66,2662,77,757,99,999,99,959,
%T A099052 595,66,9669,696,676,77,2772,66,303,353,535,525,66,66,919,39193,99,
%U A099052 181,66,33,595,323,232,434,94349,323,33,88,525,101,11,383,99,88,4884,44
%N A099052 All palindromes of length greater than 1 in the decimal expansion of e, ordered by the ending position of the palindrome. Multiple terms ending at the same position are ordered by the starting position of the palindrome.
%H A099052 Michael S. Branicky, <a href="/A099052/b099052.txt">Table of n, a(n) for n = 1..10000</a>
%o A099052 (Python)
%o A099052 from sympy import E
%o A099052 def ispal(s): return all(s[i] == s[-1-i] for i in range(len(s)//2))
%o A099052 def aupto(maxdigs):
%o A099052     digits_e = str(E.n(maxdigs+4))[2:]
%o A099052     return [int(s) for s in (digits_e[j:k+1] for k in range(1, maxdigs)
%o A099052         for j in range(k)) if s[0] != '0' and ispal(s)]
%o A099052 print(aupto(240)) # _Michael S. Branicky_, Jun 28 2021
%Y A099052 Cf. A001113 (e).
%K A099052 nonn,base
%O A099052 1,1
%A A099052 Matthew Howells (mathmatt(AT)gmail.com), Nov 13 2004
%E A099052 Offset changed and a(50) and beyond from _Michael S. Branicky_, Jun 28 2021