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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
[talk]
Sequence of the Day for June 21
A003415:a (n) = n′ |
n: a (0) = a (1) = 0, a ( prime) = 1, a (m n) = m a (n) + n a (m) |
- { 0, 0, 1, 1, 4, 1, 5, 1, 12, 6, 7, 1, 16, ... }
f (x) |
g (x) |
( f g )′ = f ′g + f g ′ |
(ab)′ = a′ b + a b′ |
1′ = 0 |
Sequences in the News
- 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: 274207281, also discovered by Curtis Cooper.
- Mar 02 2014 Fredrik Johansson announces a computation of the partition number p(10 20) ≈ 1.8381765 × 10 11140086259, the largest known term of A000041.
- Dec 06 2013 Microsoft launches a challenge to find large non-Mersenne primes, A138837.
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).