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

%I A290787 #29 Dec 21 2022 14:52:48
%S A290787 1,8,44,83,265,378,58,267,783,2890,289,5802,6781,9866,12390,15274,
%T A290787 4288,9223,22764,30890,6595,42130,49725,58010,1575,76770,87305,7670,
%U A290787 110835,123890,53786,127309,168575,11048,10389,1884,164216,116326,86857,188924,73351,15241,30690,81318,45139,157378,511828,41849,594784,638890
%N A290787 a(n) is the position of the first occurrence of n^3 in the concatenation of the positive integers in decimal representation.
%H A290787 Michael S. Branicky, <a href="/A290787/b290787.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..100 from Zhining Yang)
%e A290787 3^3 = 27, so a(3) = 44 because the digit string "27" first occurs beginning at the 44th digit of the string
%e A290787   s = "12345678910111213141516171819202122232425262728...":
%e A290787 .
%e A290787 .                  1         2         3         4
%e A290787 Position: 12345678901234567890123456789012345678901234567...
%e A290787                                                      vv
%e A290787        s: 12345678910111213141516171819202122232425262728...
%e A290787                                                      ^^
%t A290787 T = StringJoin @@ ToString /@ Range@ 700000; Table[StringPosition[T, ToString[ n^3], 1][[1, 1]], {n, 50}] (* _Giovanni Resta_, Aug 11 2017 *)
%o A290787 (VBA)
%o A290787 Sub test()
%o A290787 Dim i&, t$, s$(1 To 125000)
%o A290787 For i = 1 To 125000
%o A290787 s(i) = i
%o A290787 Next
%o A290787 t = Join(s, "")
%o A290787 For i = 1 To 50
%o A290787 Debug.Print InStr(t, i ^ 3); ",";
%o A290787 Next
%o A290787 End Sub
%Y A290787 Cf. A031297, A290647.
%K A290787 nonn,look,base
%O A290787 1,2
%A A290787 _Zhining Yang_, Aug 10 2017