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A051806
Numbers with nonzero multiplicative digital root 4.
2
4, 14, 22, 27, 39, 40, 41, 58, 72, 85, 89, 93, 98, 104, 114, 122, 127, 139, 140, 141, 158, 172, 185, 189, 193, 198, 202, 207, 212, 217, 220, 221, 245, 249, 254, 266, 270, 271, 277, 294, 309, 319, 333, 338, 346, 364, 379, 383
OFFSET
1,1
FORMULA
A051802^-1(4)
MATHEMATICA
mdr4Q[n_]:=NestWhile[Times@@(IntegerDigits[#]/.(0->1))&, n, #>9&]==4; Select[ Range[ 400], mdr4Q] (* Harvey P. Dale, Jul 02 2021 *)
CROSSREFS
Part of histogram of A051802.
Sequence in context: A185008 A165721 A197638 * A034051 A199984 A044437
KEYWORD
nonn,easy,base
AUTHOR
Dan Hoey, Dec 09 1999
STATUS
approved