A030144 Primes in which parity of digits alternates.

2, 3, 5, 7, 23, 29, 41, 43, 47, 61, 67, 83, 89, 101, 103, 107, 109, 127, 149, 163, 167, 181, 307, 347, 349, 367, 383, 389, 503, 509, 521, 523, 541, 547, 563, 569, 587, 701, 709, 727, 743, 761, 769, 787, 907, 929, 941, 947, 967, 983, 2129, 2141, 2143, 2161, 2309

Offset

1,1

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Formula

A010051(a(n)) * A228710(a(n)) = 1. - Reinhard Zumkeller, Aug 31 2013

Example

2129 is a term as 2, 1, 2 and 9 have even and odd parity alternately.

Mathematica

Join[{2, 3, 5, 7}, Select[Prime[Range[400]], Union[Abs[Differences[Boole/@ EvenQ[ IntegerDigits[#]]]]] == {1}&]] (* Harvey P. Dale, Jul 26 2011 *)

Prog

(Haskell)
a030144 n = a030144_list !! (n-1)
a030144_list = filter ((== 1) . a228710) a000040_list
-- Reinhard Zumkeller, Aug 31 2013

Crossrefs

Intersection of A000040 and A030141.

Cf. A030143, A030152.

Sequence in context: A106116 A091727 A240920 * A343590 A343591 A323578

Adjacent sequences: A030141 A030142 A030143 * A030145 A030146 A030147

Keyword

nonn,base

Author

Patrick De Geest

Extensions

Offset corrected by Reinhard Zumkeller, Aug 31 2013

Status

approved