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%I #7 Apr 30 2019 21:48:45
%S 2,0,1,0,2,0,0,1,0,1,0,1,3,1,1,0,3,0,0,5
%N Number of palindromic decagonal (10-gonal) numbers with exactly n digits.
%C Number of terms in A307827 with exactly n digits.
%H G. J. Simmons, <a href="/A002778/a002778_2.pdf">Palindromic powers</a>, J. Rec. Math., 3 (No. 2, 1970), 93-98. [Annotated scanned copy] See page 95.
%e There are only two 5 digit decagonal numbers that are palindromic, 27972 and 76867. Thus, a(5)=2.
%t A307827 = {0, 1, 232, 27972, 76867, 25555552, 7154664517, 158229922851, 2028787878202, 2040061600402, 2733623263372, 52667666676625, 675972505279576, 28519896169891582, 73542836563824537, 74529570707592547, 25552469511596425552, 27835145788754153872, 62740719088091704726, 67047523077032574076, 77979812588521897977, 107838025535520838701};
%t Table[Length[ Select[A307827, IntegerLength[#] == n || (n == 1 && # == 0) &]], {n, 20}]
%Y Cf. A001107, A307827, A307829, A307830, A307807.
%K nonn,base,more
%O 1,1
%A _Robert Price_, Apr 30 2019