[seqfan] Re: moving to wiki

Douglas McNeil d.mcneil at qmul.ac.uk
Thu Aug 27 00:36:14 CEST 2009


>> 3) Whole database access, e.g, for
>> wide-scope quality checks, conversion to printed form, etc.
>>
>> It won't be possible to copy the whole database.
>> But gzipped versions of parts will be available just as they are now.

</lurk>

I'm very much looking forward to the Wiki: I've had my OEIS-parsing code 
sitting on a shelf pending its arrival, as I didn't want to flood NJAS' 
inbox with a thousand minor little changes.  (Last digits of decimal 
constants, for example, or hundreds of SAGE programs.)

The pattern-matching actually works decently: it now can successfully 
verify a fair fraction of the formula-based ones (including many 
generating functions and recurrences) and sufficiently simple "N such that 
X" entries.  Editing in bulk means only having to write one code for each 
class of sequences, which is handy.

One thing which would be very nice from my perspective, and would be a 
perfect collaborative project, is an OEIS style guide.  Diversity has its 
advantages, and some is unavoidable, but the following is a little much:

--
sum( z^(m7^2)/(1-z^((m+1)^2)), m=1..inf)
sum(k=1,n,mu(lcm(n,k))^2)
sum(k>=1,1/b^(c^k)/c^k)
sum{j=0..floor((k+1)/2), (-1)^(k-j)*C(k-j+1, j-1)}
sum{1<=k<=n, GCD(k,n)=1} a(k)
sum{p=primes,p|n} mu(b(p,n))
sum_{n=1 to infinity)
sum C(n+k, 2k)(-1)^(n-k), k=0, .., n
Sum(k=0..n, (-1)^k*T(n,k))
Sum(a(k):1<=k<=n)
Sum(k*T(n,k),k=1..n)
Sum{((-1)^i)*T(i,n-i): i=0,1,...,n)
Sum{d(i)*9^i: i=0,1,....,m}
Sum{d(i-1)-d(i): d(i)<d(i-1), i=0,1,...,m}
Sum{n=1 to infinity} a(n)/n
Sum{T(n-k, i), k<=i<=n-k}
Sum{T(n-k, i)}, 1<=i<=k for 1<=k<=n-1
Sum{k|n k<=sqrt(n)}
Sum_{k>=0} x^(2^k-1)
Sum_{m = -infinity..infinity}
Sum_{k, 0<=k<=n}(-1)^k*A038137(n,k)
Sum_{ d divides n } mu(d)
Sum_{ primes p with 3 <= p <= n} a(n-p)
Sum[x^i,{i,0,p}]
Sum[a(n)/n!, n>=1]
Sum[d|gcd(n, A034386(n)), moebius(d) ]
Sum[k=0..n, k^m ]
Sum[k>=1, log(k)/{(k+1)*4^k} * C(2n, n)]
--

which isn't even exhaustive.  There are four or five different things all 
going by the name of "expansion of X", different conventions about whether 
the generating function is really the exponential generating function, and 
so on, which it'd be nice to have an official policy on.  You don't want 
to spend too much time navel-gazing, of course, but one of the advantages 
of wikification is that a house style guide could develop organically as 
questions emerge..


Doug, who fiercely opposes the use of a period as a multiplication symbol

--
Queen Mary College, University of London      "Still creating worlds..
Mathematical Sciences, Astronomy Unit          .. but now with an accent!"




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