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.

A261910 Numbers n which are neither palindromes nor the sum of two palindromes, with property that subtracting the largest palindrome < n from n gives a number which is the sum of two palindromes.

Original entry on oeis.org

21, 32, 43, 54, 65, 76, 87, 98, 201, 1031, 1041, 1042, 1051, 1052, 1053, 1061, 1062, 1063, 1064, 1071, 1072, 1073, 1074, 1075, 1081, 1082, 1083, 1084, 1085, 1086, 1091, 1092, 1093, 1094, 1095, 1096, 1097, 1101, 1103, 1104, 1105, 1106, 1107, 1108, 1109, 1123, 1124, 1125, 1126, 1127, 1128, 1129, 1134, 1135, 1136, 1137, 1138, 1139, 1145, 1146, 1147, 1148, 1149, 1153
Offset: 1

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Author

N. J. A. Sloane, Sep 10 2015

Keywords

Comments

These are the numbers with palindromic order 3 (see A261913).
More than the usual number of terms are shown in order to clarify the difference between this sequence and A035137.

Crossrefs

A261911 Numbers n which are neither palindromes nor the sum of two palindromes, with property that the largest palindrome which when subtracted from n yields the sum of two palindromes is not the palindromic floor of n (A261423(n)), but rather the next palindrome below that.

Original entry on oeis.org

1099, 1143, 1154, 1165, 1176, 1187, 1198, 1209, 1264, 1275, 1286, 1297, 1308, 1319, 1385, 1396, 1407, 1418, 1429, 1517, 1528, 1539, 1638, 1649, 1759, 10099, 10155, 10199, 10299, 10366, 10399, 10499, 10577, 10599, 10699, 10799, 11809, 12819, 13829, 14839
Offset: 1

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Author

N. J. A. Sloane, Sep 10 2015

Keywords

Comments

These are the numbers with palindromic order 4 (see A261913).

Crossrefs

A261913 The palindromic order of n (defined in Comments).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 1, 2
Offset: 0

Views

Author

N. J. A. Sloane, Sep 10 2015

Keywords

Comments

Order 1: palindromes (A002113);
Order 2: not order 1 but is the sum of two palindromes (A261907);
Order 3: not order 1 or 2, but n - previous_palindrome(n) (i.e., n - A261914(n)) gives a number of order 2 (A261910);
Order 4: not order 1, 2, or 3, but subtracting previous_palindrome(previous_palindrome(n)) gives a number of order 2 (A261911);
Order 5: not orders 1, 2, 3, or 4 (A261912).

Crossrefs

Closely related to A261675. See also A088601.

Formula

a(n) = A088601(n). - R. J. Mathar, Feb 14 2023
Showing 1-3 of 3 results.