%I #12 Feb 03 2021 23:12:40
%S 1,3,11,19,37,55,87,119,169,4,12,20,38,56,88,120,170,21,39,57,89,121,
%T 171,58,90,122,172,123,173,124,174,125,175,126,176,127,177,128,178,
%U 129,179,130,180,131,181,132,182,133,183,134,184
%N Atomic numbers in the periodic table of the elements, read downwards along 50 columns, up to the 9th period.
%C This finite sequence has 218 members. Atomic numbers > 218 are not members.
%C This sequence assumes simple extrapolation rather than recent research. - _J. Lowell_, Jan 26 2021
%e ======================================================
%e ................... STRUCTURE OF ....................
%e ........ THE PERIODIC TABLE OF THE ELEMENTS .........
%e ................... (50 columns) ....................
%e ======================================================
%e 1) X................................................X
%e 2) XX..........................................XXXXXX
%e 3) XX..........................................XXXXXX
%e 4) XXX................................XXXXXXXXXXXXXXX
%e 5) XXX................................XXXXXXXXXXXXXXX
%e 6) XXXX..................XXXXXXXXXXXXXXXXXXXXXXXXXXXX
%e 7) XXXX..................XXXXXXXXXXXXXXXXXXXXXXXXXXXX
%e 8) XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
%e 9) XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
%e ======================================================
%Y Cf. A099955, A134984, A138723, A138724, A138726, A138727.
%K fini,nonn,tabf
%O 1,2
%A _Omar E. Pol_, Mar 26 2008, Jan 25 2009