# [seqfan] Re: gentle reminder

Klaus Brockhaus klaus-brockhaus at t-online.de
Fri Mar 12 08:43:29 CET 2010

```Suggestion for some additional items (with negative examples):

binomial(n, m) (not Binomial[n, m])

%F A173741 t(n,m,q)=Binomial[n, m] + 2*q*If[m*(n - m) > 0, 1, If[(n - 2) *(m - 1) >= 1, Binomial[n - 2, m - 1], 0]]

tanh(x) (not Tanh[x])
floor(x) (not Floor[x])

%N A096613 Values of n such that Floor[n Tanh[Pi]] == Floor[(n+1) Tanh[Pi]].

sqrt(n) (not Sqrt[n], sqrt2 etc.)

%F A173568 t(n,q)=(Sum[(1 + (-1)^n)*(1 + Sqrt[q])^m, {m, 1, n}] + Sum[(1 + (-1)^n)*(1 - Sqrt[q])^m, {m, 1, n}])/4;even n only:
%N A111566 a(n)=((1+sqrt8)(2+sqrt2)^n+(1-sqrt8)(2-sqrt2)^n)/2

arccosh(n) (not ArcCosh[n])

%N A173121 a(n)=Sinh[2ArcCosh[n]]^2 = 4*n^2*(n^2-1)
%N A173129 a(n)= Cosh[2 n ArcCosh[n]]

A rule for the beginning of a sentence, formula etc. would be helpful,
something like "Except for ordinary English words (neighbor, nilpotent
etc.), those spellings are also used at the beginning of a line / sentence".

Two fun items, *not* for inclusion - look up those misspellings if you like!
both (not booth)
conjecture ( not conjicture)

```