A217761 Numbers whose square has a square number of decimal digits.

0, 1, 2, 3, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94

Offset

1,3

Links

Table of n, a(n) for n=1..67.

Example

32^2 is 1024, which has 2^2 = 4 digits.

Prog

(R) sq=(1:10)^2; sqsqd=c(); i=0; while(length(sqsqd)<500) { if(floor(log10(i^2)+1)%in%sq) sqsqd=c(sqsqd, i); i=i+1 }

Crossrefs

Cf. A000290, A179935.

Sequence in context: A239593 A214658 A334489 * A004843 A173353 A032815

Adjacent sequences: A217758 A217759 A217760 * A217762 A217763 A217764

Keyword

nonn,easy,base

Author

Kevin L. Schwartz and Christian N. K. Anderson, Mar 23 2013

Status

approved