A385570 a(n) is the least positive integer k such that 10^(k/A386725(k)) has at least n correct decimal digits of Pi.

1, 1, 81, 85, 87, 785, 1221, 5669, 5669, 193967, 279002, 296009, 893696, 893696, 42601399, 48857271, 98608238, 936331413

Offset: 1

Author

Stefano Spezia, Jul 31 2025

Keywords

• nonn
• base
• more

Examples

			   n   approximated value of Pi
   -   ------------------------
   1    3.16227766016837933...
   2    3.16227766016837933...
   3    3.14002073072468031...
   4    3.14105848907489924...
   5    3.14154190501421816...
   6    3.14159426168000789...
   7    3.14159239635221012...
   8    3.14159265464843386...
   9    3.14159265464843386...
  10    3.14159265302248860...
  11    3.14159265351804869...
  12    3.14159265358299421...
  13    3.14159265358975264...
  14    3.14159265358975264...
  15    3.14159265358979960...
  16    3.14159265358979359...
  17    3.14159265358979322...
  ...
		

Links

• Index entries for sequences related to the number Pi.

Crossrefs

Cf. A000796, A386725.

Programs

Mathematica

A386725[n_]:=10^(n/Round[n/Log10[Pi]]); a[n_]:=Module[{k=1},While[RealDigits[A386725[k],10,n][[1]]!=RealDigits[Pi,10,n][[1]], k++]; k]; Array[a,10]