OFFSET
1,2
COMMENTS
This is not a permutation of the natural numbers; for instance, 100 (or any number ending in "100") does not appear in this sequence since the last two digits of S will never sum to 0, 00, or 100. - Jim Nastos, Mar 13 2014
LINKS
E. Angelini, The sum rhymes [Cached copy, with permission]
EXAMPLE
a(3) = 1+2 = 3;
a(4) = 2+3 = 5;
a(5) = 3+5 = 8;
a(6) = 5+8 = 13;
a(7) = 1+3 = 4;
a(8) = 3+4 = 7;
a(9) = 4+7 = 11;
a(10) = 12 because 1+1 = 2 is already in the sequence (as a(2)), and 12 is the smallest unused integer ending with "2";
a(11) = 23 because both 1+2 = 3 and 13 are already in the sequence (as a(3) and a(6), respectively);
a(12) = 15 because 2+3 = 5 is a(5);
a(13) = 1+5 = 6.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Eric Angelini, Mar 14 2014
STATUS
approved