A143993 Composite numbers n such that the sum of prime factors of n (counted with multiplicity) terminates n as a substring.

4, 18, 220, 230, 246, 366, 444, 624, 1166, 1323, 1462, 1530, 1992, 2230, 2406, 2625, 2730, 3024, 3125, 3182, 3286, 3484, 3606, 3760, 4220, 5733, 6372, 6435, 7592, 8658, 8856, 9585, 9747, 10143, 10850, 11232, 11655, 13176, 13230, 13275, 13760, 14792

Offset

1,1

Comments

Equals A071173 without its first term. [From R. J. Mathar, Sep 13 2008]

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

a(9)=1166=2*11*53 and 2+11+53=66 and 1166 ends in 66.

Mathematica

nssQ[n_]:=Module[{idn=IntegerDigits[n], ss=IntegerDigits[Total[ Flatten[ Table[#[[1]], {#[[2]]}]&/@FactorInteger[n]]]]}, Take[idn, -Length[ss]] == ss]; Select[Range[2, 15000], !PrimeQ[#]&&nssQ[#]&] (* Harvey P. Dale, Sep 03 2012 *)

Crossrefs

Sequence in context: A275965 A363313 A071173 * A145660 A246531 A278565

Adjacent sequences: A143990 A143991 A143992 * A143994 A143995 A143996

Keyword

base,nonn

Author

Gil Broussard, Sep 07 2008

Extensions

Definition clarified by N. J. A. Sloane, Sep 03 2012

Status

approved