A036921 Numbers n such that digit sum of n equals digit sum of 'juxtaposition' and 'sum' of its prime factors (counted with multiplicity).

4, 22, 27, 94, 121, 166, 202, 265, 274, 346, 355, 382, 438, 454, 517, 526, 562, 634, 706, 852, 913, 915, 922, 1086, 1111, 1165, 1219, 1255, 1282, 1507, 1626, 1633, 1642, 1822, 1894, 1903, 1966, 2067, 2155, 2173, 2182, 2227, 2265, 2326, 2362, 2409, 2434

Offset: 1

Author

Patrick De Geest, Jan 04 1999

Keywords

• nonn
• base

Crossrefs

Cf. A006753, A036920, A019506.

Programs

Mathematica

d[n_]:=IntegerDigits[n]; co[n_,k_]:=Nest[Flatten[d[{#,n}]]&,n,k-1]; t={}; Do[If[!PrimeQ[n]&&Total[d[n]]==Total[d[Total[Times@@@(x=FactorInteger[n])]]]==Total[Flatten[d[co@@@x]]],AppendTo[t,n]],{n,4,2435}]; t (* Jayanta Basu, Jun 04 2013 *)