login
Composite numbers k such that prime = abs(smallest digit of k - sum of all the other digits of k).
0

%I #5 Aug 23 2024 19:38:18

%S 14,16,18,20,24,25,27,30,35,36,38,42,46,49,50,52,57,58,63,64,68,69,70,

%T 72,74,75,81,85,86,92,94,96,102,104,106,110,112,115,117,120,121,122,

%U 124,126,133,135,140,142,144,148,153,159,160,162,166,168,171,175,177,184

%N Composite numbers k such that prime = abs(smallest digit of k - sum of all the other digits of k).

%e 14(3=abs(1-4)), 16(5=abs(1-6)), 18(7=abs(1-8)), 20(2=2-0)

%t sdkQ[n_]:=Module[{id=IntegerDigits[n],mid},mid=Min[id];PrimeQ[Abs[mid-Total[DeleteCases[ id,mid,1,1]]]]]; cnkQ[n_]:=CompositeQ[n]&&sdkQ[n]; Select[Range[200],cnkQ] (* _Harvey P. Dale_, Aug 23 2024 *)

%Y Cf. A000040, A002808, A156979.

%K nonn,base

%O 1,1

%A _Juri-Stepan Gerasimov_, Mar 15 2009, May 25 2009

%E Entries checked by _R. J. Mathar_, May 19 2010