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A057943 Numbers k such that the smallest palindromic pseudoprime to base k is 101101. 1
2, 51, 60, 75, 96, 200, 207, 279, 288, 348, 402, 432, 464, 492, 500, 531, 555, 590, 646, 652, 662, 675, 695, 732, 750, 790, 843, 855, 860, 888, 894, 920, 927, 983, 984, 1074, 1102, 1139, 1140, 1150, 1152, 1163, 1164, 1203, 1215, 1230, 1251, 1278, 1283, 1336 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..10000

C. K. Caldwell, Carmichael number

C. K. Caldwell, Pseudoprimes

C. Rivera, Carmichael Numbers

Index entries for sequences related to pseudoprimes

EXAMPLE

2 is a term since 101101 is the least Fermat pseudoprime to base 2 (A001567) which is also a palindrome in base 10 (A002113).

3 is not a term since the least Fermat pseudoprime to base 3 (A005935) which is also a palindrome in base 10 is 121.

MATHEMATICA

palinComps = Select[Range[2, 101100], PalindromeQ[#] && CompositeQ[#] &]; seqQ[n_] := PowerMod[n, 101100, 101101] == 1 && AllTrue[palinComps, PowerMod[n, #-1, #] != 1 &]; Select[Range[1336], seqQ] (* Amiram Eldar, Jan 30 2020 *)

CROSSREFS

Cf. A001567, A002113, A002997.

Sequence in context: A084107 A203746 A230561 * A037419 A078165 A180110

Adjacent sequences:  A057940 A057941 A057942 * A057944 A057945 A057946

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, Oct 15 2000

STATUS

approved

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Last modified April 11 22:01 EDT 2021. Contains 342888 sequences. (Running on oeis4.)