A030146 Squares-of-primes in which no two adjacent digits have the same parity.

4, 9, 25, 49, 121, 169, 361, 529, 961, 12769, 16129, 18769, 32761, 72361, 76729, 78961, 96721, 212521, 214369, 436921, 452929, 458329, 1038361, 1630729, 1852321, 3892729, 5230369, 5470921, 5650129, 5812921, 5870929, 7230721

Offset

1,1

Comments

Intersection of A030141 and A001248. - Michel Marcus, Feb 06 2015

Links

Giovanni Resta, Table of n, a(n) for n = 1..10000

Formula

a(n) = A030145(n)^2. - Giovanni Resta, Aug 16 2018

Mathematica

Join[{4, 9}, Select[Prime[Range[4000]]^2, Union[Sort/@OddQ/@Partition[IntegerDigits[#], 2, 1]]=={{False, True}}&]] (* Harvey P. Dale, Feb 22 2011 *)

Crossrefs

Cf. A030145, A030152.

Sequence in context: A359757 A052043 A188836 * A229970 A038771 A158146

Adjacent sequences: A030143 A030144 A030145 * A030147 A030148 A030149

Keyword

nonn,base

Author

Patrick De Geest

Extensions

Definition clarified by Harvey P. Dale, Feb 23 2011

Offset changed by Michel Marcus, Feb 06 2015

Status

approved