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A088997
Base-10 numbers such that a(n) plus any nonnegative palindrome less than a(n) does not yield a palindrome.
2
12, 23, 34, 45, 1011, 1020, 1021, 1029, 1031, 1038, 1041, 1047, 1051, 1061, 1065, 1071, 1074, 1081, 1091, 1092, 1101, 1112, 1121, 1130, 1131, 1132, 1139, 1141, 1142, 1148, 1151, 1152, 1157, 1161, 1162, 1171, 1172, 1175, 1181, 1182, 1191, 1192, 1201
OFFSET
1,1
COMMENTS
This sequence cannot contain palindromes since 0 is a palindrome and any palindrome plus 0 is also a palindrome.
EXAMPLE
a(2) = 23 because 23 plus any smaller palindromic number (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22) does not yield a palindrome.
MAPLE
reverse := proc (d) local n, m; m := 0; n := d; while n>0 do m := m*10+(n mod 10); n := (n-(n mod 10))/10; od; m; end; isPalindromic := proc (n) if (n=reverse(n)) then true; else false; fi; end; n := 0; found := false; nosum := []; for c to 1400 do; while not(found) and n<c do; if isPalindromic(c+n) then found := true; else n := nextPal(n) fi; od; if not(found) then nosum := [op(nosum), c]; n := 0; else n := 0; found := false; fi; od; nosum;
MATHEMATICA
dnypQ[n_]:=NoneTrue[n+Select[Range[n-1], PalindromeQ], PalindromeQ];
Module[ {upto=1500}, Select[Range[upto], !PalindromeQ[#]&&dnypQ[#]&]] (* Harvey P. Dale, Dec 02 2021 *)
PROG
(PARI) is(n)=!for(k=0, n-1, is_A002113(k)&&is_A002113(n+k)&&return) \\ M. F. Hasler, Apr 26 2014
CROSSREFS
Sequence in context: A127421 A112131 A233032 * A049852 A045532 A255729
KEYWORD
base,nonn
AUTHOR
Chuck Seggelin (barkeep(AT)plastereddragon.com), Dec 01 2003
EXTENSIONS
Definition corrected and further edits by M. F. Hasler, Apr 26 2014
STATUS
approved