OFFSET
1,1
COMMENTS
2999 = A062802(4) is the smallest term of this sequence for which the second iterated sum of digits is not the final sum; i.e. the smallest requiring three summations (2+9+9+9=29, 2+9=11, 1+1=2 and all three sums are prime). (The corresponding statement about the very large A062802(5) is not true because a large number of smaller nonprimes of the same digit length also have the digit sum 2999, the least being 29999..., where 333 9's follow the 2.). A062802, a sequence of primes, is a subsequence of this sequence and of A070027.
Additional terms can be generated by finding the next number whose digit sum is a prime already in the sequence. - Felix Fröhlich, Jun 13 2014
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..1000
EXAMPLE
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Rick L. Shepherd, Apr 13 2002
EXTENSIONS
Terms corrected by Felix Fröhlich, Jun 13 2014
STATUS
approved