A129913 a(n) is the number of ways of producing n, with an expression like: +- 1 # 2 # 3 # 4 # 5 # 6 # 7 # 8 # 9, where each # is replaced by any one of +,-,*,/; and the value is computed going left to right.

694, 299, 143, 171, 156, 156, 183, 155, 167, 434, 160, 140, 129, 111, 89, 147, 114, 201, 171, 94, 87, 90, 68, 95, 130, 130, 44, 120, 41, 72, 76, 72, 50, 81, 50, 53, 137, 49, 46, 78, 41, 75, 36, 61, 28, 123, 35, 86, 47, 40, 40, 47, 40, 37, 109, 61, 32, 58, 23, 53

Offset

0,1

Links

Don Reble, Table of n, a(n) for n = 0..1000

Don Reble, C++ program to compute sequence

Example

Going left-to-right, +1-2/3-4-5*6/7+8*9 = 0; and there are 694 such expressions which yield zero, so a(0)=694.

Crossrefs

Sequence in context: A004240 A004241 A322154 * A031946 A049356 A020385

Adjacent sequences: A129910 A129911 A129912 * A129914 A129915 A129916

Keyword

easy,nonn

Author

Jason Rodgers (Jason628(AT)gmail.com), Jun 05 2007, Jun 06 2007

Extensions

Corrected and edited by Don Reble, Jun 23 2008

Status

approved