A109513 Let k be an m-digit integer. Then k is a Pithy number if the k-th m-tuple in the decimal digits of Pi (after the decimal point) is the string k.

1, 19, 94, 3542, 7295, 318320, 927130, 939240, 688370303, 7682437410, 7996237896, 89594051933

Offset: 0

Author

Colin Rose, Jul 01 2005

Keywords

• base
• more
• nonn

Examples

			1 is a term because the first digit in Pi (after the decimal point) is 1.
19 is a term because the 19th pair of digits (after the decimal point) in Pi is 19:
      1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19
  3. 14 15 92 65 35 89 79 32 38 46 26 43 38 32 79 50 28 84 19 ...
		

Links

• David G. Andersen, The Pi-Search Page.

Crossrefs

Cf. A000796, A109514, A057679, A057680.

Programs

Mathematica

PithyNumbers[m_] := Module[{cc = m(10^m)+m, sol, aa}, sol = Partition[RealDigits[Pi, 10, cc] // First // Rest, m]; Do[aa = FromDigits[sol[[i]]]; If[aa==i, Print[{i, aa}]], {i, Length[sol]}];] Example: PithyNumbers[4] produces all 4-digit Pithy numbers

Extensions

a(8)-a(11) from J. Volkmar Schmidt, Dec 17 2023