A201019 Primes whose multiplicative digital root is 6.

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

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