A051806 Numbers with nonzero multiplicative digital root 4.

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

Links

Table of n, a(n) for n=1..48.

Index entries for 10-automatic sequences.

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

Adjacent sequences: A051803 A051804 A051805 * A051807 A051808 A051809

Keyword

nonn,easy,base

Author

Dan Hoey, Dec 09 1999

Status

approved