From d9d608bc32ee31c73c139e1b68e4eb6315205e8d Mon Sep 17 00:00:00 2001
From: Tim Jones <jonest@sagenet.com>
Date: Wed, 8 Dec 2021 15:01:01 -0600
Subject: [PATCH] Add sequence A000201 (lower Wythoff sequence).

---
 oeis.py               |  4 ++++
 tests/test_A000201.py | 13 +++++++++++++
 2 files changed, 17 insertions(+)
 create mode 100644 tests/test_A000201.py

diff --git a/oeis.py b/oeis.py
index d9b949e..5b321e8 100644
--- a/oeis.py
+++ b/oeis.py
@@ -691,6 +691,10 @@ def A070939(i: int = 0) -> int:
     """Length of binary representation of n."""
     return len(f"{i:b}")
 
+@oeis.from_function()
+def A000201(n: int) -> int:
+    """Lower Wythoff sequence: a(n) = floor(n * phi), where phi = (1 + sqrt(5))/2 (golden ratio)"""
+    return (math.floor(n * (1 + math.sqrt(5))/2.0))
 
 def main() -> None:  # pylint: disable=too-many-branches
     """Command line entry point."""
diff --git a/tests/test_A000201.py b/tests/test_A000201.py
new file mode 100644
index 0000000..b63c25f
--- /dev/null
+++ b/tests/test_A000201.py
@@ -0,0 +1,13 @@
+from oeis import A000201
+
+
+def test_sequence():
+    from_oeis_org = [
+        int(i)
+        for i in """1, 3, 4, 6, 8, 9, 11, 12, 14, 16, 17, 19, 21, 22, 24, 25,
+        27, 29, 30, 32, 33, 35, 37, 38, 40, 42, 43, 45, 46, 48, 50, 51, 53, 55,
+        56, 58, 59, 61, 63, 64, 66, 67, 69, 71, 72, 74, 76, 77, 79, 80, 82, 84,
+        85, 87, 88, 90, 92, 93, 95, 97, 98, 100, 101, 103, 105, 106, 108, 110
+        """.split(", ")
+    ]
+    assert A000201[1 : len(from_oeis_org) + 1] == from_oeis_org