A325323 Palindromes in base 10 that are not Brazilian.

1, 2, 3, 4, 5, 6, 9, 11, 101, 131, 151, 181, 191, 313, 353, 373, 383, 727, 787, 797, 919, 929, 10201, 10301, 10501, 10601, 11311, 11411, 12421, 12721, 12821, 13331, 13831, 13931, 14341, 14741, 15451, 15551, 16061, 16361, 16561, 16661, 17471, 17971, 18181, 18481, 19391, 19891, 19991

Offset

1,2

Comments

The terms >= 11 of this sequence are either prime palindromes which are not Brazilian, or square of primes (except 121).

Links

Amiram Eldar, Table of n, a(n) for n = 1..1000

Mathematica

brazQ[n_] := Module[{b = 2, found = False}, While[b < n - 1 && Length @ Union[IntegerDigits[n, b]] > 1, b++]; b < n - 1]; Select[Range[20000], PalindromeQ[#] && !brazQ[#] &] (* Amiram Eldar, Apr 14 2021 *)

Prog

(PARI) isb(n) = for(b=2, n-2, my(d=digits(n, b)); if(vecmin(d)==vecmax(d), return(1))); \\ A125134
isp(n) = my(d=digits(n)); d == Vecrev(d); \\ A002113
isok(n) = !isb(n) && isp(n); \\ Michel Marcus, Apr 22 2019

Crossrefs

Intersection of A002113 and A220570.

Complement of A325322 with respect to A002113.

Cf. A088882 (Palindromes not repdigits).

Sequence in context: A220570 A341057 A299297 * A331016 A125155 A365416

Adjacent sequences: A325320 A325321 A325322 * A325324 A325325 A325326

Keyword

nonn,base

Author

Bernard Schott, Apr 20 2019

Status

approved