The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

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 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A212123 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. 8
 1, 3, 4, 7, 8, 10, 14, 16, 19, 20, 25, 29, 32, 34, 35, 41, 46, 50, 53, 55, 56, 63, 68, 71, 77, 81, 82, 84, 92 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS First differs from A213363 at a(12). LINKS FORMULA a(n) = A212124(n)/2. EXAMPLE Example 1: written as a triangle in which row i is related to the (i-1)st level of nucleus. Triangle begins: 1; 3,    4; 7,    8,  10; 14,  16,  19,  20; 25,  29,  32,  34,  35; 41,  46,  50,  53,  55,  56; 63,  68,  71,  77,  81,  82,  84; ... Example 2: written as an irregular triangle in which row j is related to the j-th shell of nucleus. Note that in this case row 4 has only one term. Triangle begins: 1; 3,   4; 7,   8, 10; 14, 16, 19, 20, 25; 29, 32, 34, 35, 41; 46, 50, 53, 55, 56, 63; 68, 71, 77, 81, 82, 84, 92; ... CROSSREFS Partial sums of A212121. Other versions are A210983, A212013, A213363, A213373. Cf. A000292, A004006, A212122, A212124. Sequence in context: A338733 A210983 A213363 * A213373 A332059 A229081 Adjacent sequences:  A212120 A212121 A212122 * A212124 A212125 A212126 KEYWORD nonn,tabf,hard,more AUTHOR Omar E. Pol, Jun 03 2012 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 8 16:34 EST 2021. Contains 349596 sequences. (Running on oeis4.)