OFFSET
1,3
COMMENTS
Conjecture: For any prime number p there exists a positive integer k such that k*p is an Ulam number.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Ulam Sequence.
Wikipedia, Ulam number.
EXAMPLE
a(3) = 29 because 5*29 gives the Ulam number 145 and this is the smallest Ulam number divisible by 5.
MATHEMATICA
lst1 = ReadList["https://oeis.org/A002858/b002858.txt", {Number, Number}]; lst = {}; Do[n=1; While[!IntegerQ[k=lst1[[n]][[2]]/Prime[m]], n++]; AppendTo[lst, k], {m, 1, 100}]; lst
CROSSREFS
KEYWORD
nonn
AUTHOR
Frank M Jackson, Apr 01 2020
STATUS
approved