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A097640 Numbers n such that n=(d_1+d_2+...+d_k)*prime(d_1+d_2+...+d_k) where d_1 d_2 ... d_k is the decimal expansion of n. 2

%I #6 Nov 21 2013 12:48:21

%S 152,207,444,1098

%N Numbers n such that n=(d_1+d_2+...+d_k)*prime(d_1+d_2+...+d_k) where d_1 d_2 ... d_k is the decimal expansion of n.

%e 444 is in the sequence because 444=(4+4+4)*prime(4+4+4).

%t denQ[n_]:=Module[{tidn=Total[IntegerDigits[n]]},n==tidn Prime[tidn]]; Select[Range[1100],denQ] (* _Harvey P. Dale_, May 08 2012 *)

%Y Cf. A097641.

%K base,fini,full,nonn

%O 1,1

%A _Farideh Firoozbakht_, Aug 21 2004

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Last modified April 25 08:27 EDT 2024. Contains 371964 sequences. (Running on oeis4.)