A138336 First occurrence of exactly n consecutive numbers after A138335(n) (A138335(n) excluded).

18, 27, 127, 1111

Offset

1,1

Comments

Such number digits after decimal point of number Pi where the approximation to the number Pi by a root of a polynomial of 2 degree does not improve the accuracy exactly n next digits.

It seems that sequence A138335, and therefore also this sequence, are ill defined. - M. F. Hasler, May 21 2025

Links

Table of n, a(n) for n=1..4.

Example

a(1)=18 because 3.141592653589793238 (18 digits) is root of -3061495 + 674903*x + 95366*x^2 and 3.1415926535897932385 (19 digits) also is root of that same polynomial -3061495 + 674903*x + 95366*x^2.

Crossrefs

Cf. A138335, A138337.

Sequence in context: A396672 A279108 A038632 * A349485 A166630 A154920

Adjacent sequences: A138333 A138334 A138335 * A138337 A138338 A138339

Keyword

dead

Author

Artur Jasinski, Mar 15 2008

Extensions

There are comments in the entry for A138335 which may cast doubt on the validity of this and related sequences. - N. J. A. Sloane, Mar 19 2008

Status

approved