A052054 - OEIS

A052054

Composite numbers all of whose prime factors (considered with multiplicity) share at least one digit.

4, 8, 9, 16, 25, 27, 32, 39, 46, 49, 58, 64, 69, 81, 92, 93, 111, 116, 117, 119, 121, 125, 128, 129, 143, 159, 169, 184, 187, 207, 209, 219, 221, 232, 243, 247, 249, 254, 256, 259, 265, 279, 289, 295, 299, 309, 323, 329, 333, 339, 341, 343, 351, 361, 368, 387

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

LINKS

Table of n, a(n) for n=1..56.

EXAMPLE

E.g., 92 = 2 * 2 * 23 is a term because the sets {2}, {2} and {2,3} share the digit 2.

MATHEMATICA

Select[2~Range~500, !PrimeQ@#&&And@@IntersectingQ@@@Subsets[ IntegerDigits[ First/@FactorInteger[#]], {2}]&] (* Giorgos Kalogeropoulos, May 09 2019 *)

CROSSREFS

Cf. A052053.

Sequence in context: A090515 A075309 A175031 * A046447 A087244 A080062

Adjacent sequences: A052051 A052052 A052053 * A052055 A052056 A052057

KEYWORD

nonn,base

AUTHOR

Patrick De Geest, Dec 15 1999

EXTENSIONS

Offset 1 from Michel Marcus, May 09 2019

Name clarified by Jon E. Schoenfield, May 10 2019

STATUS

approved