Marinada '21

[lang=hr] Elemente Fibonaccijeva niza generiramo tako da zbrojimo prethodna dva člana u nizu, počevši s dvije jedinice. Prvih nekoliko elemenata niza su \[ 1, 1, 2, 3, 5, 8, 13, 21, 34, ... \] Koliki je zbroj parnih elemenata Fibbonaccijeva niza koji nisu veći od $4 \cdot 10^6$? [/lang] [lang=en] Elements of the Fibbonacci sequence are generated by summing up the previous two elements in the sequence, starting with two ones. The first few elements are \[ 1, 1, 2, 3, 5, 8, 13, 21, 34, ... \] What is the sum of even elements of the Fibbonacci sequence that are not greater than $4 \cdot 10^6$? [/lang]