A169903 Primitive primes in carryless arithmetic mod 10.

21, 23, 25, 27, 29, 51, 56, 201, 209, 227, 229, 241, 243, 261, 263, 287, 289, 551, 2023, 2027, 2043, 2047, 2061, 2069, 2081, 2089, 2207, 2209, 2221, 2223, 2263, 2267, 2281, 2287, 2401, 2407, 2421, 2423, 2441, 2449, 2483, 2489, 2603, 2609

Offset

1,1

Comments

Define the units in carryless arithmetic mod 10 to be the numbers 1, 3, 7 and 9 (these divide any number). A prime is a number N, not a unit, whose only factorizations are of the form N = u * M, where u is a unit.

A prime is primitive if it not the carryless product of a smaller prime and a unit.

A subsequence of A169887.

Links

David Applegate, Table of n, a(n) for n = 1..843 (all primitive primes with <= 6 digits)

Index entries for sequences related to carryless arithmetic

Crossrefs

Cf. A004520, A059729, A168294, A168541, A169885, A169886, A169884, A169887.

Cf. A058943, A058945.

Sequence in context: A143712 A163396 A375214 * A095447 A095443 A095441

Adjacent sequences: A169900 A169901 A169902 * A169904 A169905 A169906

Keyword

nonn,base

Author

David Applegate, Marc LeBrun and N. J. A. Sloane, Jul 11 2010

Status

approved