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A201019 Primes whose multiplicative digital root is 6. 2
23, 47, 61, 227, 281, 283, 347, 443, 449, 467, 487, 647, 683, 743, 769, 773, 797, 821, 823, 829, 863, 887, 967, 977, 1123, 1213, 1231, 1283, 1289, 1321, 1471, 1481, 1487, 1489, 1627, 1697, 1741, 1783, 1823, 1847, 1861, 1873, 2113, 2131, 2237, 2243, 2267, 2273, 2281, 2287, 2311 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Complement of A201020 with respect to A034053.

LINKS

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

EXAMPLE

Prime 227 is in sequence because 2*2*7=28, 2*8=16, 1*6=6.

MATHEMATICA

dr6Q[n_]:=NestWhile[Times@@IntegerDigits[#]&, n, #>9&]==6; Select[ Prime[ Range[ 400]], dr6Q] (* Harvey P. Dale, Jun 16 2016 *)

CROSSREFS

Cf. A201020 (composite numbers whose multiplicative digital root is 6),  A034053 (numbers whose multiplicative digital root is 6).

Sequence in context: A097361 A073025 A209193 * A244092 A042046 A042044

Adjacent sequences:  A201016 A201017 A201018 * A201020 A201021 A201022

KEYWORD

nonn,base

AUTHOR

Jaroslav Krizek, Nov 25 2011

STATUS

approved

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Last modified February 29 08:26 EST 2020. Contains 332355 sequences. (Running on oeis4.)