71907

Appears in sequences

• Split positive integers into extending even groups and sum: 1+2, 3+4+5+6, 7+8+9+10+11+12, 13+14+15+16+17+18+19+20, ...at n=33A061317
• Number of n X 2 0..4 arrays of sums of 2 X 2 subblocks of some (n+1) X 3 binary array with rows and columns of the latter in lexicographically nondecreasing order.at n=12A226988
• a(1) = a(2) = 1; a(n) = ( Sum_{i|(n-1)} a(i) ) + Sum_{j|(n-2)} a(j).at n=21A293636