

A008920


Let j =  i  i_written_backwards , k = j + j_written_backwards; then k is in this sequence.


1



0, 18, 99, 198, 261, 342, 423, 504, 585, 666, 747, 828, 909, 1089, 1170, 1251, 1332, 1413, 1494, 1575, 1656, 1737, 1818, 1881, 1998, 2772, 2871, 3663, 3762, 4554, 4653, 5445, 5544, 6336, 6435, 7227, 7326, 8118, 8217, 9009, 9108, 9999, 10890, 10989, 11781
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OFFSET

1,2


COMMENTS

There were originally some terms missing from this sequence, for example 909 generated from 101001. It seems likely to me that Conway only checked generators up to 100000. It's possible to prove that there are now no missing terms of the sequence by noting that if an ndigit number is not a palindrome then the difference between it and its reversal is at least 9*10^(n/2  1).  Oscar Cunningham, Sep 10 2021


REFERENCES

J. H. Conway, personal communication.


LINKS



CROSSREFS



KEYWORD

nonn,base


AUTHOR



EXTENSIONS



STATUS

approved



