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A199984
Composite numbers whose multiplicative digital root is 4.
1
4, 14, 22, 27, 39, 72, 93, 98, 114, 122, 141, 172, 189, 198, 212, 217, 221, 249, 266, 294, 319, 333, 338, 346, 364, 391, 411, 429, 436, 492, 626, 634, 662, 712, 721, 767, 772, 776, 793, 819, 833, 891, 913, 918, 924, 931, 942, 973, 981, 1114, 1122, 1127, 1139
OFFSET
1,1
COMMENTS
Complement of A199983 with respect to A034051.
EXAMPLE
Number 172 is in sequence because 1*7*2=14, 1*4=4.
MATHEMATICA
cn4Q[n_]:=NestWhile[Times@@IntegerDigits[#]&, n, #>9&]==4; Select[Select[ Range[ 1200], CompositeQ], cn4Q] (* Harvey P. Dale, Apr 28 2018 *)
CROSSREFS
Cf. A199983 (primes whose multiplicative digital root is 4).
Cf. A034051 (numbers whose multiplicative digital root is 4).
Sequence in context: A197638 A051806 A034051 * A044437 A298008 A279414
KEYWORD
nonn,base
AUTHOR
Jaroslav Krizek, Nov 13 2011
STATUS
approved