A036920 Composite numbers n such that digit sum of n equals digit sum of sum of its prime factors (counted with multiplicity).

4, 22, 27, 94, 105, 114, 121, 150, 166, 202, 204, 222, 224, 265, 274, 315, 342, 346, 355, 382, 438, 445, 450, 454, 517, 526, 540, 562, 612, 634, 640, 706, 841, 852, 913, 915, 922, 1068, 1086, 1111, 1120, 1122, 1138, 1165, 1185, 1200, 1219, 1221, 1230

Offset: 1

Author

Patrick De Geest, Jan 04 1999

Keywords

• nonn
• base

Crossrefs

Cf. A006753, A036921, A019506.

Programs

Mathematica

ds[n_]:=Total[IntegerDigits[n]]; t={}; Do[If[!PrimeQ[n]&&ds[n]==ds[Total[ Times@@@FactorInteger[n]]],AppendTo[t,n]],{n,4,1230}]; t (* Jayanta Basu, Jun 04 2013 *)

Extensions

Title made more precise by Sean A. Irvine, Nov 30 2020