A290787 a(n) is the position of the first occurrence of n^3 in the concatenation of the positive integers in decimal representation.

1, 8, 44, 83, 265, 378, 58, 267, 783, 2890, 289, 5802, 6781, 9866, 12390, 15274, 4288, 9223, 22764, 30890, 6595, 42130, 49725, 58010, 1575, 76770, 87305, 7670, 110835, 123890, 53786, 127309, 168575, 11048, 10389, 1884, 164216, 116326, 86857, 188924, 73351, 15241, 30690, 81318, 45139, 157378, 511828, 41849, 594784, 638890

Offset: 1

Author

Zhining Yang, Aug 10 2017

Keywords

• nonn
• look
• base

Examples

			3^3 = 27, so a(3) = 44 because the digit string "27" first occurs beginning at the 44th digit of the string
  s = "12345678910111213141516171819202122232425262728...":
.
.                  1         2         3         4
Position: 12345678901234567890123456789012345678901234567...
                                                     vv
       s: 12345678910111213141516171819202122232425262728...
                                                     ^^
		

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..10000 (terms 1..100 from Zhining Yang)

Crossrefs

Cf. A031297, A290647.

Programs

Mathematica

T = StringJoin @@ ToString /@ Range@ 700000; Table[StringPosition[T, ToString[ n^3], 1][[1, 1]], {n, 50}] (* Giovanni Resta, Aug 11 2017 *)

VBA

Sub test()
Dim i&, t$, s$(1 To 125000)
For i = 1 To 125000
s(i) = i
Next
t = Join(s, "")
For i = 1 To 50
Debug.Print InStr(t, i ^ 3); ",";
Next
End Sub