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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

Table of n, a(n) for n=1..29.

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

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