Nevenproduct

Nevenproduct is a term encountered mainly in informal mathematics discussions and programming forums. It is not a standard mathematical object, and its meaning varies by source. In many contexts it is used as a placeholder name for an operation whose exact definition is given within a problem or code snippet rather than in formal literature.

One common interpretation is as a function on finite sequences: nevenproduct(s) denotes the product of the elements in even-numbered positions (using 1-based indexing). For example, nevenproduct([a1, a2, a3, a4]) = a2 · a4. If there are no elements in even positions, the value is the neutral element for multiplication, i.e., 1.

Another interpretation treats nevenproduct as a binary operation on integers: nevenproduct(a, b) = a · b if both a and b are even; otherwise it equals 0. Example: nevenproduct(4, 6) = 24; nevenproduct(3, 4) = 0.

Some discussions define nevenproduct as the product of all even numbers in a set or list. In that reading, nevenproduct({1, 2, 3, 4}) = 2 · 4 = 8; if no even numbers are present, some authors use 1 as the empty product, others use 0 or undefined.

Because there is no standard definition, readers should consult the specific source to determine which interpretation is intended. See also product, even numbers, and sequence indexing for related concepts.