A050726 Decimal expansion of 5^n contains no pair of consecutive equal digits (probably finite).

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 14, 15, 16, 17, 18, 19, 20, 21, 22, 27, 28, 29, 32

Offset: 0

Author

Patrick De Geest, Sep 15 1999

Keywords

• nonn
• base

Comments

No further terms up to 3000. - Harvey P. Dale, May 11 2011

No further terms up to 80000. - Ivan N. Ianakiev, Aug 31 2019

Examples

			5^32 = 23283064365386962890625.
		

Crossrefs

Cf. A008839, A046263, A046271.

Programs

Maple

q:= n-> (s-> andmap(i-> s[i]<>s[i+1], [$1..length(s)-1]))(""||(5^n)):
select(q, [$0..200])[];  # Alois P. Heinz, Mar 07 2024

Mathematica

Select[Range[0,3000],And@@(First[#]!=Last[#]&/@Partition[ IntegerDigits[ 5^#],2,1])&] (* Harvey P. Dale, May 11 2011 *)
Select[Range[0,40],SequenceCount[IntegerDigits[5^#],{x_,x_}]==0&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jun 12 2020 *)