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A261924 Numbers that are the sum of two palindromes of the same length. 2
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 22, 33, 44, 55, 66, 77, 88, 99, 110, 121, 132, 143, 154, 165, 176, 187, 198, 202, 212, 222, 232, 242, 252, 262, 272, 282, 292, 302, 303, 312, 313, 322, 323, 332, 333, 342, 343, 352, 353, 362, 363, 372, 373, 382, 383, 393 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

Theorem: For a fixed value of d, adding two palindromes of length d in all possible ways produces 19 distinct sums if d=1, and 17*19^floor((d-1)/2) distinct sums if d>1. (The number of palindromes with d digits is 10 if d = 1, otherwise 9*10^floor((d-1)/2).) - N. J. A. Sloane, Dec 06 2015

LINKS

N. J. A. Sloane, Table of n, a(n) for n = 1..12956

CROSSREFS

Cf. A002113, A261921, A261925, etc.

Sequence in context: A246086 A194417 A246093 * A255421 A255407 A269171

Adjacent sequences:  A261921 A261922 A261923 * A261925 A261926 A261927

KEYWORD

nonn,base

AUTHOR

David Applegate and N. J. A. Sloane, Sep 17 2015

EXTENSIONS

Modified to include the zero palindrome. - N. J. A. Sloane, Dec 06 2015

STATUS

approved

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Last modified June 21 07:27 EDT 2021. Contains 345358 sequences. (Running on oeis4.)