A080531 Number of nucleons in longest known radioactive decay series ending with Lead 208 ("thorium series"), reversed.

208, 208, 212, 212, 216, 220, 224, 224, 228, 228, 232, 236, 240, 244, 248, 252, 252, 256, 260, 264, 268, 272

Offset

0,1

Comments

The numbers are all equivalent to 0 mod 4. The sequence was submitted reversed, as it is open in the past. It is unknown if reversed decay series are finite (the "island of stability" hypothesis).

Links

Table of n, a(n) for n=0..21.

C. Heilman, The Pictorial Periodic Table

Formula

a(n)=A080535(n)+A080539(n).

Crossrefs

Cf. A080529, A080530, A080532.

Sequence in context: A232346 A052093 A103477 * A123136 A092153 A283152

Adjacent sequences: A080528 A080529 A080530 * A080532 A080533 A080534

Keyword

nonn,hard

Author

Ralf Stephan, Feb 20 2003

Status

approved