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%I #22 Jun 19 2016 03:06:19
%S 121,341,451,671,781,961,1111,1271,1331,1441,1661,1681,1891,1991,2101,
%T 2201,2321,2501,2651,2761,2911,2981,3091,3131,3421,3641,3721,3751,
%U 4061,4141,4331,4411,4631,4681,4741,4961,5041,5071,5371,5401,5611,5731,5921
%N Composite numbers with all divisors congruent to 1 mod 10.
%H Reinhard Zumkeller, <a href="/A068872/b068872.txt">Table of n, a(n) for n = 1..1000</a>
%t fQ[n_] := ! PrimeQ@ n && Union@ Mod[ First /@ FactorInteger@ n, 10] == {1}; Rest@ Select[ Range@ 5950, fQ] (* _Robert G. Wilson v_, Mar 04 2012 *)
%o (Haskell)
%o a068872 n = a068872_list !! (n-1)
%o a068872_list = filter
%o (all (== 1) . map (`mod` 10) . a027750_row) a002808_list
%o -- _Reinhard Zumkeller_, Mar 08 2012
%o (PARI) is(n)=!isprime(n) && n>1 && vecmax(factor(n)[,1]%10)==1 \\ _Charles R Greathouse IV_, Jun 19 2016
%Y Cf. A027750, A002808.
%K nonn
%O 1,1
%A _Amarnath Murthy_, Mar 19 2002
%E More terms from _Sascha Kurz_, Mar 23 2002
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