3v4l.org

run code in 150+ php & hhvm versions
Bugs & Features
<?php $i = 1; for($f = 0; $f <= 20; $f++) { echo "F".$f." = ".($i+pow($i,$f))."\n"; $i++; }
based on ajlg1
Output for 4.3.6 - 7.1.0
F0 = 2 F1 = 4 F2 = 12 F3 = 68 F4 = 630 F5 = 7782 F6 = 117656 F7 = 2097160 F8 = 43046730 F9 = 1000000010 F10 = 25937424612 F11 = 743008370700 F12 = 23298085122494 F13 = 793714773254158 F14 = 29192926025390640 F15 = 1152921504606846992 F16 = 4.8661191875667E+19 F17 = 2.1859115597387E+21 F18 = 1.0412735029791E+23 F19 = 5.24288E+24 F20 = 2.7821842944695E+26
Output for 4.3.0 - 4.3.5
F0 = 2 F1 = 4 F2 = 12 F3 = 68 F4 = 630 F5 = 7782 F6 = 117656 F7 = 2097160 F8 = 43046730 F9 = 1000000010 F10 = 25937424612 F11 = 743008370700 F12 = 23298085122494 F13 = 793714773254158 F14 = 29192926025390639 F15 = 1152921504606846992 F16 = 4.8661191875667E+19 F17 = 2.1859115597387E+21 F18 = 1.0412735029791E+23 F19 = 5.24288E+24 F20 = 2.7821842944695E+26