%I #15 Jul 19 2023 15:22:59
%S 9,22,34,35,36,38,39,44,56,57,58,63,65,66,75,78,85,87,88,93,95,111,
%T 224,225,226,228,232,242,252,262,272,282,292,322,333,344,345,346,348,
%U 354,355,356,357,358,364,365,366,368,369,374,375,376,377,378,384,385,386
%N Composites k such that (smallest digit of k) + (multiplicity of smallest digit of k) is an even composite.
%H Harvey P. Dale, <a href="/A154528/b154528.txt">Table of n, a(n) for n = 1..1000</a>
%e 9 (composite) is a term because 9 + 1 = 10 (even composite);
%e 22 (composite) is a term because 2 + 2 = 4 (even composite);
%e 34 (composite) is a term because 3 + 1 = 4 (even composite).
%p frequdig := proc(n,dig) local f,d ; f := 0 ; for d in convert(n,base,10) do if d = dig then f :=f+1; end if; end do; f ; end proc:
%p A054054 := proc(n) min(op(convert(n,base,10)) ) ; end proc:
%p for n from 1 to 500 do c := A002808(n) ; sdg := A054054(c) ; a := sdg +frequdig(c,sdg) ; if type(a,'even') and not isprime(a) then printf("%d,",c ) ; end if; end do: # _R. J. Mathar_, May 05 2010
%t ecQ[n_]:=Module[{idn=IntegerDigits[n],s,c},s=Min[idn];c=s+Count[idn,s];EvenQ[c]&&AllTrue[ {n,c},CompositeQ]]; Select[Range[400],ecQ] (* _Harvey P. Dale_, Jul 19 2023 *)
%Y Cf. A002808.
%K nonn,base
%O 1,1
%A _Juri-Stepan Gerasimov_, Jan 11 2009
%E Corrected (28 replaced with 38, 269 with 369) by _R. J. Mathar_, May 05 2010
%E Name and Example section edited by _Jon E. Schoenfield_, Feb 11 2019
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