1,1

Comment from Joshua Zucker (joshua.zucker(AT)gmail.com), May 26 2007. This appears to be a concatenation of five puzzles:

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.

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.

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

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

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

Sequence in context: A122128 A114430 A033418 this_sequence A129887 A106136 A095605

Adjacent sequences: A120307 A120308 A120309 this_sequence A120311 A120312 A120313

nonn,dumb

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