Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:1,2,3,5,8,13,21,34,55,89, By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.
main.ts
import { sum } from "../util/util.ts"
import { isEven } from "../util/util.ts"
import { fibonachi } from "../util/sequence/fibonachi.ts"
import { takeUntil } from "../util/functional.ts"
function main() {
const a = takeUntil(fibonachi(), n => n > 4_000_000)
.filter(isEven)
.reduce(sum)
console.log(a)
100 + 200 //?
}
main()