This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A333997 #16 Oct 07 2020 05:44:58
%S A333997 1,2,6,10,26,42,58,74,90,106,234,362,874,1386,1898,2410,2922,3434,
%T A333997 68970,134506,138602,142698,146794,89450,154986,159082,163178,167274,
%U A333997 109930,175466,437610,699754,961898,1224042,1486186,1748330
%N A333997 Number of electrons per subshell in element Z=n expressed as a 56-bit unsigned integer.
%C A333997 This is a memory-efficient way of encoding the number of electrons per subshell of all known elements.
%H A333997 Zachary Russ, <a href="/A333997/b333997.txt">Table of n, a(n) for n = 1..118</a>
%H A333997 Wikipedia, <a href="https://en.wikipedia.org/wiki/Electron_configurations_of_the_elements_(data_page)">Electron configurations of the elements (data page)</a>
%e A333997 |-----|----------------------------------------------------------------------------|
%e A333997 | | a(n) [bin] |
%e A333997 | n | Electrons per Subshell |
%e A333997 | | 7p|7s| 6d | 6p|6s| 5f | 5d | 5p|5s| 4f | 4d | 4p|4s| 3d | 3p|3s| 2p|2s|1s |
%e A333997 |-----|----|--|----|---|--|----|----|---|--|----|----|---|--|----|---|--|---|--|---|
%e A333997 | 1 | 000 00 0000 000 00 0000 0000 000 00 0000 0000 000 00 0000 000 00 000 00 01 |
%e A333997 | 2 | 000 00 0000 000 00 0000 0000 000 00 0000 0000 000 00 0000 000 00 000 00 10 |
%e A333997 | 3 | 000 00 0000 000 00 0000 0000 000 00 0000 0000 000 00 0000 000 00 000 01 10 |
%e A333997 | 4 | 000 00 0000 000 00 0000 0000 000 00 0000 0000 000 00 0000 000 00 000 10 10 |
%e A333997 | 5 | 000 00 0000 000 00 0000 0000 000 00 0000 0000 000 00 0000 000 00 001 10 10 |
%e A333997 | 6 | 000 00 0000 000 00 0000 0000 000 00 0000 0000 000 00 0000 000 00 010 10 10 |
%e A333997 | . | . |
%e A333997 | . | . |
%e A333997 | . | . |
%e A333997 | 113 | 001 10 1010 110 10 1110 1010 110 10 1110 1010 110 10 1010 110 10 110 10 10 |
%e A333997 | 114 | 010 10 1010 110 10 1110 1010 110 10 1110 1010 110 10 1010 110 10 110 10 10 |
%e A333997 | 115 | 011 10 1010 110 10 1110 1010 110 10 1110 1010 110 10 1010 110 10 110 10 10 |
%e A333997 | 116 | 100 10 1010 110 10 1110 1010 110 10 1110 1010 110 10 1010 110 10 110 10 10 |
%e A333997 | 117 | 101 10 1010 110 10 1110 1010 110 10 1110 1010 110 10 1010 110 10 110 10 10 |
%e A333997 | 118 | 110 10 1010 011 10 1110 1010 110 10 1110 1010 110 10 1010 110 10 110 10 10 |
%e A333997 |-----|----------------------------------------------------------------------------|
%o A333997 (C++) typedef unsigned char Subshell; uint64_t a(Subshell _1s=0x0, Subshell _2s=0x0, Subshell _2p=0x0, Subshell _3s=0x0, Subshell _3p=0x0, Subshell _3d=0x0, Subshell _4s=0x0, Subshell _4p=0x0, Subshell _4d=0x0, Subshell _4f=0x0, Subshell _5s=0x0, Subshell _5p=0x0, Subshell _5d=0x0, Subshell _5f=0x0, Subshell _6s=0x0, Subshell _6p=0x0, Subshell _6d=0x0, Subshell _7s=0x0, Subshell _7p=0x0) {return ((uint64_t)_1s) + ((uint64_t)_2s << 2 ) + ((uint64_t)_2p << 4 ) + ((uint64_t)_3s << 7 ) + ((uint64_t)_3p << 9 ) + ((uint64_t)_3d << 12) + ((uint64_t)_4s << 16) + ((uint64_t)_4p << 18) + ((uint64_t)_4d << 21) + ((uint64_t)_4f << 25) + ((uint64_t)_5s << 29) + ((uint64_t)_5p << 31) + ((uint64_t)_5d << 34) + ((uint64_t)_5f << 38) + ((uint64_t)_6s << 42) + ((uint64_t)_6p << 44) + ((uint64_t)_6d << 47) + ((uint64_t)_7s << 51) + ((uint64_t)_7p << 53);}
%Y A333997 Cf. A333662, A168208, A093907.
%K A333997 fini,nonn,full
%O A333997 1,2
%A A333997 _Zachary Russ_, Sep 05 2020