91 is Pseudoprime to 35 Bases less than 91

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Theorem

$91$ is a Fermat pseudoprime in $35$ bases less than itself:

$3, 4, 9, 10, 12, 16, 17, 22, 23, 25, 27, 29, 30, 36, 38, 40, 43, 48, 51, 53, 55, 61, 62, 64, 66, 68, 69, 74, 75, 79, 81, 82, 87, 88, 90$


Proof


Historical Note

This result is attributed by David Wells in his $1997$ work Curious and Interesting Numbers, 2nd ed. to Tiger Redman, but no corroboration can be found for this on the internet.


Sources