A199977 Primes whose multiplicative digital root is 0.

59, 101, 103, 107, 109, 239, 251, 257, 269, 293, 307, 349, 353, 401, 409, 439, 457, 479, 503, 509, 521, 523, 541, 547, 563, 569, 577, 587, 599, 601, 607, 619, 653, 659, 691, 701, 709, 757, 787, 809, 853, 857, 859, 877, 907, 947, 997, 1009, 1013, 1019, 1021

Offset

1,1

Comments

Complement of A199978 with respect to A034048.

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

Prime 239 is in sequence because 2*3*9 = 45, 4*5 = 20, 2*0 = 0.

Maple

mdr:= proc(n) local L, r;
  r:= n;
  while r >= 10 do
    r:= convert(convert(r, base, 10), `*`)
  od;
  r
end proc:
select(mdr=0, [seq(ithprime(i), i=1..1000)]); # Robert Israel, Feb 28 2021

Mathematica

digRoot[n_] := Module[{k = n}, While[k > 9, k = Times @@ IntegerDigits[k]]; k]; Select[Range[1200], PrimeQ[#] && digRoot[#] == 0 &] (* T. D. Noe, Nov 23 2011 *)

Crossrefs

Cf. A199978 (nonprime numbers whose multiplicative digital root is 0).

Sequence in context: A142152 A112804 A240339 * A134573 A106869 A147092

Adjacent sequences: A199974 A199975 A199976 * A199978 A199979 A199980

Keyword

nonn,base

Author

Jaroslav Krizek, Nov 13 2011

Status

approved