+/*
+#define K 0x0555555555555555LL
+#define MASK 0xFFFFFFFFFFFFFFFFLL
+static
+uint64_t k_lut[] PROGMEM = {
+ 16LL*K, 17LL*K, 18LL*K, 19LL*K,
+ 20LL*K, 21LL*K, 22LL*K, 23LL*K,
+ 24LL*K, 25LL*K, 26LL*K, 27LL*K,
+ 28LL*K, 29LL*K, 30LL*K, 31LL*K };
+*/
+/* the same as above but precomputed to avoid compiler warnings */