A120310 - OEIS

%I #6 Nov 12 2013 15:36:44

%S 98,72,77,49,54,20,10,1,11,2,13,4,17,8,25,7,1,2,2,6,3,12,4,20,5,15,20,

%T 13,18,11,0,0,4,9,8,18,12,27

%N See comments lines.

%C Comment from _Joshua Zucker_, May 26 2007. This appears to be a concatenation of five puzzles:

%C 98,72,77,49,54,20,25,10,15,5,10,0,5,5,10,0,5,5,10,0,... (start with 98, then write down the product of its digits, then add 5, repeat) - see A129887.

%C 10,1,11,2,13,4,17,8,25,7,... (start with 10; write down the sum of its digits; add last two terms; repeat) - see A129888.

%C 1,2,2,6,3,12,4,20,5,30,6,42,... (write down n, then n(n+1)) - see A129889.

%C 15,20,13,18,11,16,9,14,... (interleave two arithmetic progressions of difference -2).

%C 0,0,4,9,8,18,12,27,16,36,20,... (interleave two arithmetic progressions 0,4,8,12,... and 0,9,18,27,...)

%K nonn,dumb,unkn

%O 1,1

%A Sydney Richardson (AmyNStiers(AT)aol.com), Aug 16 2006