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Selected Recent Additions

  • A239797 Decimal expansion of .
  • A238271 Decimal expansion of .
  • A237042 UPC check digits.
  • A236603 Lowest canonical Gray cycles of length .
  • A235365 Smallest odd prime factor of .
  • A234522 Decimal expansion of .
  • A233748 Number of graphs on n vertices with edges colored with at most four interchangeable colors under the symmetries of the full edge permutation group.
  • A232499 Number of unit squares, aligned with a Cartesian grid, completely within the first quadrant of a circle centered at the origin ordered by increasing radius.
  • A231963 Concatenate with its UPC check digit.
  • A230624 Numbers with property that for every base , there is a number such that , where is the sum of digits in the base expansion of .

Sequence of the Day

Sequence of the Day for January 18

A085667: Decimal expansion of
e ↑↑ 4 = eeee = 2.331504399...  ⋅   10 1656520
As late as December 2011, this was the irrational constant in the OEIS with the largest integer part, having 1656521 digits to the left of the decimal point.

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On this day...

  • January 18, 1711 James Stirling enrolls at Balliol College Oxford as a Snell Exhibitioner.
  • January 18, 1856 Luigi Bianchi is born in Parma.
  • January 18, 1897 A bill is introduced in the Indiana House of Representatives proclaiming .

Sequences in the News

  • Dec 25 2018 German Heise-News "integers, please" column explains A003173 and OEIS.
  • Feb 01 2018 Alphabet announced a $8,589,869,056 = $A000396(6) stock buyback.
  • Jan 03 2018 Largest known term of A000043 announced: 77232917.
  • Nov 18 2016 PrimeGrid proves that 10223 is not a Sierpinski number, since 10223 × 2 31172165 + 1 is prime. So no changes to A076336 for now.
  • Sep 14 2016 Tom Greer discovers the twin primes 2996863034895 × 2 1290000 ± 1 using PrimeGrid, TwinGen and LLR.
  • Jan 19 2016 Largest known term of A000043 announced: 74207281, also discovered by Curtis Cooper.

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