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User:Charles R Greathouse IV
From OeisWiki
Vice President of the OEIS and Editor-in-Chief, interested primarily in computational number theory and allied fields.
I can be contacted via my Talk page here, or by email: my first name (charles) at my initials (crg4) dot com. Other email addresses may work as well.
User:Charles R Greathouse IV/Averages | Early draft of an article. |
User:Charles R Greathouse IV/Chase sequences | 'Chase sequences': Axxxxxx refers to Ayyyyyy, which refers to Azzzzzz... |
User:Charles R Greathouse IV/Favorites | Some of my favorite sequences. |
User:Charles R Greathouse IV/Format | Discusses the correct format of b-files and how to repair ill-formatted b-files. |
User:Charles R Greathouse IV/Junk | Disreputable publishers, journals, etc. |
User:Charles R Greathouse IV/Keywords | Information on keywords: when to use them, new ones to add, etc. |
User:Charles R Greathouse IV/Metadata | Plans for OEIS metadata: keywords, categories, the index, etc. |
User:Charles R Greathouse IV/Pari | Some PARI/GP tools. |
User:Charles R Greathouse IV/Programs | Programs in the OEIS: types, format, etc. |
User:Charles R Greathouse IV/Projects | Other mathematical databases, fingerprint databases, and similar projects |
User:Charles R Greathouse IV/Properties | Sequence properties and classes |
User:Charles R Greathouse IV/Rule of thumb | Sequences should take 1 hour to prepare for submission. |
User:Charles R Greathouse IV/Tables of special primes | Types of primes and their densities |
User:Charles R Greathouse IV/To do | Sequences to work on and b-files to fix. |
User:Charles R Greathouse IV/Vanity | Sequences named after their discoverer. |
User:Charles R Greathouse IV/Wiki | Tools for the OEIS wiki. |
Projects:
Useful links:
- Features Wishlist, User:Russ Cox/OEIS Server Features, Suggested Projects
- Deleted sequences
- Suggested pre-submit checklist
- Requested articles
- Editing history: sequence, wiki
- References on proof attempts: P vs. NP, Riemann hypothesis
Sequence of the Day for January 24
A001021:12 n, n ≥ 0 |
{ 1, 12, 144, 1728, 20736, 248832, 2985984, ... }
These numbers are the basis of the duodecimal numeral system. Some of us might be old enough to remember in school having to learn multiplication tables up to 12 rather than 10, and perhaps also having to learn at least the small powers of 12. Starting with 12, this sequence appears in the film Vollmond (1998, dir. Fredi Murer), when the children write it on the sidewalk at night.
Sequences in the News
- November 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.
- September 14, 2016 Tom Greer discovers the twin primes 2996863034895 × 2 1290000 ± 1 using PrimeGrid, TwinGen and LLR.
- January 19, 2016 Largest known term of A000043 announced: 274207281, also discovered by Curtis Cooper.
- March 2, 2014 Fredrik Johansson announces a computation of the partition number , the largest known term of A000041.
- December 6, 2013 Microsoft launches a challenge to find large non-Mersenne primes, A138837.
- May 13, 2013 H. A. Helfgott submits a proof of the weak Goldbach conjecture, i.e. for odd numbers as sums of three primes: A007963 has no more zeroes.
- January 25, 2013 Curtis Cooper discovers a new member of A000043, 57885161. Its index is not known but is at least 48.
- January 13, 2013 The winners of the contest for new sequences in the OEIS at JMM 2013 were announced: A187824, A187771, and A187761.
Complaints
I strive to live up to the highest ethical standards. If you feel that I have wrongly rejected one of your sequences (or otherwise failed to meet the expected standards), please leave a note at Complaints About Editing where it will be reviewed. I hope that in all cases you will first contact me (through the pink comment boxes, on my user page, or by email).