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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A260254 Number of ways to write n as sum of two palindromes in decimal representation.

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%I A260254 #23 Aug 15 2015 08:04:18
%S A260254 1,1,2,2,3,3,4,4,5,5,5,5,5,4,4,3,3,2,2,1,1,0,2,1,1,1,1,1,1,1,1,1,0,2,
%T A260254 1,1,1,1,1,1,1,1,1,0,3,1,1,1,1,1,1,1,1,1,0,3,1,1,1,1,1,1,1,1,1,0,4,1,
%U A260254 1,1,1,1,1,1,1,1,0,4,1,1,1,1,1,1,1,1
%N A260254 Number of ways to write n as sum of two palindromes in decimal representation.
%C A260254 a(A035137(n)) = 0; a(A260255(n)) > 0.
%H A260254 Reinhard Zumkeller, <a href="/A260254/b260254.txt">Table of n, a(n) for n = 0..10000</a>
%H A260254 Hugo Pfoertner, <a href="/A260254/a260254_2.png">Plot of first 10^6 terms</a>
%H A260254 Hugo Pfoertner, <a href="/A260254/a260254_1.png">Plot of first 3*10^7 terms</a>
%F A260254 a(n) = sum{A136522(n - A002113(k)): k = 1..floor(n/2)}.
%e A260254 .   n | a(n) |                                n | a(n) |
%e A260254 . ----+------+--------------------------    ----+------+--------------
%e A260254 .   0 |    1 |  0                            21 |    0 |  ./.
%e A260254 .   1 |    1 |  1                            22 |    2 |  22, 11+11
%e A260254 .   2 |    2 |  2, 1+1                       23 |    1 |  22+1
%e A260254 .   3 |    2 |  3, 2+1                       24 |    1 |  22+2
%e A260254 .   4 |    3 |  4, 3+1, 2+2                  25 |    1 |  22+3
%e A260254 .   5 |    3 |  5, 4+1, 3+2                  26 |    1 |  22+4
%e A260254 .   6 |    4 |  6, 5+1, 4+2, 3+3             27 |    1 |  22+5
%e A260254 .   7 |    4 |  7, 6+1, 5+2, 4+3             28 |    1 |  22+6
%e A260254 .   8 |    5 |  8, 7+1, 6+2, 5+3, 4+4        29 |    1 |  22+7
%e A260254 .   9 |    5 |  9, 8+1, 7+2, 6+3, 5+4        30 |    1 |  22+8
%e A260254 .  10 |    5 |  9+1, 8+2, 7+3, 6+4, 5+5      31 |    1 |  22+9
%e A260254 .  11 |    5 |  11, 9+2, 8+3, 7+4, 6+5       32 |    0 |  ./.
%e A260254 .  12 |    5 |  11+1, 9+3, 8+4, 7+5, 6+6     33 |    2 |  33, 22+11
%e A260254 .  13 |    4 |  11+2, 9+4, 8+5, 7+6          34 |    1 |  33+1
%e A260254 .  14 |    4 |  11+3, 9+5, 8+6, 7+7          35 |    1 |  33+2
%e A260254 .  15 |    3 |  11+4, 9+6, 8+7               36 |    1 |  33+3
%e A260254 .  16 |    3 |  11+5, 9+7, 8+8               37 |    1 |  33+4
%e A260254 .  17 |    2 |  11+6, 9+8                    38 |    1 |  33+5
%e A260254 .  18 |    2 |  11+7, 9+9                    39 |    1 |  33+6
%e A260254 .  19 |    1 |  11+8                         40 |    1 |  33+7
%e A260254 .  20 |    1 |  11+9                         41 |    1 |  33+8  .
%o A260254 (Haskell)
%o A260254 a260254 n = sum $ map (a136522 . (n -)) $
%o A260254                takeWhile (<= n `div` 2) a002113_list
%Y A260254 Cf. A002113, A136522, A035137, A260255.
%K A260254 nonn,base,look
%O A260254 0,3
%A A260254 _Reinhard Zumkeller_, Jul 21 2015