Status Report on Recaman's Sequence A005132 (https://oeis.org/A005132) Benjamin Chaffin, Jan 25 2018 My program logged all changes under 2^32, so from that I can extract all the holes (i.e., missing numbers) within that range. Below are all the holes under 10 million that were still unfilled at the end, around 10^230 terms. === There are several other "near misses", where the sequence gets quite low without filling the bottom-most hole. The lowest it goes after hitting 2406 is around n = 9*10^17, where it hits 963744. The most dramatic is around 1.78*10^41, where it hits 2023155 -- you can see this as a downward spike around 10^41 in the "paint dripping" log-log graph in the OEIS entry A005132. And of course you can also see that around 10^167 it drops from 2^550 (10^165) all the way down to 2^90 (10^27). Proportionally that is clearly the biggest drop, but 10^27 is still a long way from the bottom. === Recaman holes below 10^7: 852655 930058 930557 964420 966052 966727 969194 971330 971626 971866 972275 972827 976367 1007255 1007258 1007261 1007264 1007267 1007270 1007273 1010690 1017005 1022042 1036373 1049705 1137508 1137509 1138993 1139098 1139272 1141429 1141430 1145042 1145606 1148330 1149887 1659043 1661419 1723696 1723927 1973345 1985950 1986458 1991459 1991657 1993967 2015050 2021725 2023215 2023216 2025883 2027638 2028646 2028649 2028652 2279065 3063759 3063760 3064549 3080322 3257131 3259276 3268723 3269020 3270415 3271819 3277660 3281917 3291760 3297142 3611395 3615195 3995454 5082624 5269776 5305328 5914345 5914348 5921122 5921821 5924091 5953449 5969199 6073164 6075399 6121476 6129471 6139797 6159066 6166650 6166917 6980598 6988248 7033062 7242171 7255317 7710048 7808589 9159087 9574813 9577861 9580539 9585306 ======================================