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%I #9 Apr 03 2023 10:36:11
%S 2161,155801,263201,445001,617801,755401,758201,1142201,1273001,
%T 1293401,1352201,1491001,1494401,1628801,1801601,2414201,2447801,
%U 2611001,2629001,2876801,3049801,3267001,3422801,3541801,3744401,3759001,3825401,3838201,3871601,3952601
%N Primes that have the property that deleting some digit results in a prime with the same multiplicative order, or period (repeating length of 1/p).
%H C. K. Caldwell, <a href="https://t5k.org/curios/page.php/2161.html">Prime Curios</a>
%e 2161 and 211 (delete a digit from 2161) are both primes with period 30, so 2161 is in the sequence.
%t pL[n_] := MultiplicativeOrder[10, n]; hQ[n_] := Block[{s, d = IntegerDigits@n, pe}, s = Union@ Select[FromDigits /@ (Delete[d, #] & /@ Range@ Length@d), PrimeQ]; If[s != {}, pe = pL@n; s = Select[s, pe == pL@# &]]; s != {}]; Select[
%t Prime@ Range[10^5], hQ] (* _Giovanni Resta_, Jan 06 2014 *)
%Y Cf. A116075, A116076.
%K base,nonn
%O 1,1
%A G. L. Honaker and _Jud McCranie_, Feb 03 2006
%E a(5)-a(30) from _Giovanni Resta_, Jan 06 2014
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