A119931 Sum of the numbers of the matrix A111490 along a boustrophedon path: a11, a11+a21, a11+a21+a21, etc.
1, 2, 3, 4, 6, 7, 8, 10, 11, 12, 13, 15, 18, 20, 21, 22, 24, 27, 28, 29, 30
Offset: 0
Examples
If we rewrite the matrix putting on the top the upper left edge and then we sum the numbers following a boustrophedon path we have: .........../.1. ........../_____ ...........1...1.\ ........._________\ ......./.1...2...1. ....../______________ .......1...2...1...1.\ ....._________________\ .../.1...2...3...2...1. ../_____________________ ...1...2...3...1...1...1. then 1, 1+1, 1+1+1, 1+1+1+1, 1+1+1+1+2, 1+1+1+1+2+1, 1+1+1+1+2+1+1, 1+1+1+1+2+1+1+2, 1+1+1+1+2+1+1+2+1, 1+1+1+1+2+1+1+2+1+1, ... That is 1, 2, 3, 4, 6, 7, 8, 10, 11, 12, 13, 15, 18, 20, etc.
References
- G. Balzarotti and P. P. Lava, Le sequenze di numeri interi, Hoepli, 2008, p. 60.
Crossrefs
Cf. A119930.