A030097 Numbers k such that k^2 has only even digits.

0, 2, 8, 20, 22, 68, 78, 80, 92, 162, 168, 200, 202, 220, 262, 298, 478, 492, 498, 668, 680, 780, 800, 898, 908, 920, 932, 1422, 1492, 1498, 1620, 1680, 1692, 2000, 2002, 2020, 2022, 2192, 2200, 2202, 2498, 2502, 2578, 2620, 2832, 2878, 2978, 2980, 4502

Offset

1,2

Comments

A136904 is a subsequence. - Zak Seidov, Dec 03 2012

Links

Zak Seidov, Table of n, a(n) for n = 1..2000

Formula

a(n) = sqrt(A030098(n)). - Zak Seidov, Dec 03 2012

Mathematica

Select[ Range[ 3000 ], Union[ EvenQ[ IntegerDigits[ #^2 ] ] ] == {True} & ]

Prog

(PARI) is_A030097(n)=!setminus(Set(Vec(Str(n^2))), Vec("02468"))  \\ M. F. Hasler, Dec 13 2011

Crossrefs

Cf. A030098, A136904.

Sequence in context: A227127 A227399 A327098 * A136904 A043002 A108180

Adjacent sequences: A030094 A030095 A030096 * A030098 A030099 A030100

Keyword

nonn,base

Author

Patrick De Geest

Extensions

More terms from Zak Seidov, May 24 2010

Status

approved