CoefficientList[poly, var] gives a list of coefficients of powers of var in poly, starting with power 0. CoefficientList[poly, {var_1, var_2, ...}] gives an array of ...
FoldList[f, x, {a, b, ...}] gives {x, f[x, a], f[f[x, a], b], ...}.
DateList[] gives the current local date and time in the form {year, month, day, hour, minute, second}. DateList[time] gives a date list corresponding to an AbsoluteTime ...
NestList[f, expr, n] gives a list of the results of applying f to expr 0 through n times.
Reap
(Built-in Mathematica Symbol) Reap[expr] gives the value of expr together with all expressions to which Sow has been applied during its evaluation. Expressions sown using Sow[e] or Sow[e, tag_i] with ...
Delete
(Built-in Mathematica Symbol) Delete[expr, n] deletes the element at position n in expr. If n is negative, the position is counted from the end. Delete[expr, {i, j, ...}] deletes the part at position {i, ...
Thread
(Built-in Mathematica Symbol) Thread[f[args]] "threads" f over any lists that appear in args. Thread[f[args], h] threads f over any objects with head h that appear in args. Thread[f[args], h, n] threads f ...
ListConvolve[ker, list] forms the convolution of the kernel ker with list. ListConvolve[ker, list, k] forms the cyclic convolution in which the k\[Null]^th element of ker is ...
ListCorrelate[ker, list] forms the correlation of the kernel ker with list. ListCorrelate[ker, list, k] forms the cyclic correlation in which the k \[Null]^th element of ker ...
Flatten
(Built-in Mathematica Symbol) Flatten[list] flattens out nested lists. Flatten[list, n] flattens to level n. Flatten[list, n, h] flattens subexpressions with head h. Flatten[list, {{s_11, s_12, ...}, ...