login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A213373
Total number of pairs of states of the first n subshells of the nuclear shell model in which the subshells are ordered by energy level in increasing order.
7
1, 3, 4, 7, 8, 10, 14, 16, 19, 20, 25, 29, 32, 38, 40, 41, 45, 50, 57, 59, 62, 63
OFFSET
1,2
COMMENTS
First differs from A212123 at a(14). For more information see A213372.
FORMULA
a(n) = A213374(n)/2.
EXAMPLE
Written as an irregular triangle in which row j is related to the j-th shell of nucleus. Note that row 4 has only one term. Triangle begins:
1;
3, 4;
7, 8, 10;
14;
16, 19, 20, 25;
29, 32, 38, 40, 41;
45, 50, 57, 59, 62, 63;
...
CROSSREFS
Partial sums of A213371. Other versions are A210983, A212013, A212123, A213363.
Sequence in context: A210983 A213363 A212123 * A363353 A332059 A375929
KEYWORD
nonn,tabf,hard,more
AUTHOR
Omar E. Pol, Jul 16 2012
STATUS
approved