cp's OEIS Frontend

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.

Showing 1-3 of 3 results.

A261924 Numbers that are the sum of two palindromes of the same length.

Original entry on oeis.org

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
Offset: 1

Views

Author

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

Keywords

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

Crossrefs

Cf. A002113, A261921, A261925, etc.

Extensions

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

A261920 In A261907 but not the sum of two palindromes whose lengths differ by 1.

Original entry on oeis.org

10, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 124, 125, 126, 127, 128, 129, 130, 135, 136, 137, 138, 139, 140, 146, 147, 148, 149, 150, 157, 158, 159, 160, 168, 169, 170, 179, 180, 190, 211, 221, 231, 241, 251, 261, 271, 281, 291, 302, 312, 322, 332, 342
Offset: 1

Views

Author

David Applegate and N. J. A. Sloane, Sep 15 2015

Keywords

Comments

Nonpalindromes which are the sum of two palindromes but are not the sum of two palindromes whose lengths differ by 1.

Examples

			10 = 5+5 is a member, as is 109=101+8.

Crossrefs

Cf. A002113, A261907, A261921.

A261925 Nonpalindromes that are the sum of two nonzero palindromes of the same length.

Original entry on oeis.org

10, 12, 13, 14, 15, 16, 17, 18, 110, 132, 143, 154, 165, 176, 187, 198, 302, 312, 322, 332, 342, 352, 362, 372, 382, 403, 413, 423, 433, 443, 453, 463, 473, 483, 504, 514, 524, 534, 544, 554, 564, 574, 584, 605, 615, 625, 635, 645, 655, 665, 675, 685, 706, 716, 726
Offset: 1

Views

Author

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

Keywords

Crossrefs

Cf. A002113, A261921, A261924, etc.
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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