

A019445


Form a permutation of the positive integers, p_1, p_2, ..., such that the average of each initial segment is an integer, using the greedy algorithm to define p_n; sequence gives p_1 + ... + p_n.


3



1, 4, 6, 12, 20, 24, 35, 40, 54, 70, 77, 96, 117, 126, 150, 160, 187, 216, 228, 260, 273, 308, 345, 360, 400, 442, 459, 504, 522, 570, 620, 640, 693, 748, 770, 828, 851, 912, 975, 1000, 1066, 1092, 1161, 1232, 1260, 1334, 1410, 1440, 1519, 1550
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,2


COMMENTS

It appears that a(n) is divisible by n.  Michael Somos, Jan 29 2004
Somos's conjecture is proved in both Shapovalov (1996) and Venkatachala (2009).  Jeffrey Shallit, Jul 18 2023


LINKS



FORMULA



CROSSREFS



KEYWORD

nonn


AUTHOR

R. K. Guy, Tom Halverson (halverson(AT)macalester.edu)


STATUS

approved



