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A177715
The position within sqrt(n) at which n first occurs.
2
0, 4, 2, 0, 36, 38, 4, 1, 0, 88, 19, 51, 221, 318, 48, 0, 11, 98, 24, 143, 60, 40, 8, 108, 0, 144, 9, 267, 32, 188, 183, 154, 370, 44, 107, 0, 117, 25, 10, 148, 145, 107, 4, 234, 48, 298, 252, 31, 0, 102, 211, 119, 178, 352, 118, 224, 63, 9, 107, 103, 239, 130, 94, 0, 16
OFFSET
1,2
COMMENTS
Determine position from the decimal point, and define a(n)=0 for perfect squares (A000290).
LINKS
EXAMPLE
a(1)=0 because 1 is a perfect square.
a(2)=4 because the first "2" occurs at position 4 in "1.41421356...".
a(5)=36 because the first "5" occurs at position 36 in "2.236067977499789696409173668731276235"
MATHEMATICA
max = 500; a[n_] := If[IntegerQ @ Sqrt[n], 0, SequencePosition[(r = RealDigits[ FractionalPart @ Sqrt[n], 10, max])[[1]], IntegerDigits[n]][[1, 1]] - r[[2]]]; Array[a, 100] (* Amiram Eldar, Sep 25 2020 *)
CROSSREFS
Cf. A000290.
Sequence in context: A019155 A107724 A247092 * A164789 A203986 A204690
KEYWORD
nonn,base
AUTHOR
Gil Broussard, May 12 2010
STATUS
approved