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A105983 Near-repdigit semiprimes with 2 as repeated digit. 1

%I #4 Jun 11 2018 11:48:41

%S 122,202,221,226,262,422,622,922,2122,2227,2229,2722,4222,8222,20222,

%T 22223,22226,22262,22322,22522,22622,22822,25222,32222,52222,202222,

%U 222221,222223,222242,222422,223222,224222,226222,262222,272222,622222

%N Near-repdigit semiprimes with 2 as repeated digit.

%H Harvey P. Dale, <a href="/A105983/b105983.txt">Table of n, a(n) for n = 1..100</a>

%e a(2)=202 is a term because 202 is a semiprime and all digits are equal to 2 except one.

%t Rest[Select[FromDigits/@Flatten[Permutations/@Flatten[ Table[PadRight[ {n},k,2],{k,3,6},{n,0,9}],1],1],PrimeOmega[#]==2&]]//Sort (* _Harvey P. Dale_, Jun 11 2018 *)

%K base,nonn

%O 1,1

%A _Shyam Sunder Gupta_, Apr 29 2005

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Last modified April 24 18:17 EDT 2024. Contains 371962 sequences. (Running on oeis4.)