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