floydTriangle
=LAMBDA(n,
    IF(0 < n,
        LET(
            ixs, SEQUENCE(
                n, n,
                0, 1
            ),
            x, MOD(ixs, n),
            y, QUOTIENT(ixs, n),

            IF(x > y,
                "",
                x + 1 + QUOTIENT(
                    y * (1 + y),
                    2
                )
            )
        ),
        ""
    )
)