A147845 Odd positive integers a(n) such that for every odd integer m>=7 there exists a unique representation of the form m=a(p)+2a(q)+4a(r).

1, 3, 17, 19, 129, 131, 145, 147, 1025, 1027, 1041, 1043, 1153, 1155, 1169, 1171, 8193, 8195, 8209, 8211, 8321, 8323, 8337, 8339, 9217, 9219, 9233, 9235, 9345, 9347, 9361, 9363, 65537, 65539, 65553, 65555

Offset: 1

Author

Vladimir Shevelev, Nov 15 2008

Keywords

• nonn

Comments

Since, e.g., 27=17+2*3+4*1 and 17=a(3),3=a(2),1=a(1), then 27 has "coordinates" (3,2,1). Thus we have a one-to-one map of odd integers >=7 to the positive lattice points in the three-dimensional space.

Crossrefs

A145812 A145818 A033045 A033052 [From Vladimir Shevelev, Nov 19 2008]

Formula

a(n)=2A033045(n-1)+1