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 A019328 #18 Feb 26 2024 09:59:31 %S A019328 9,11,111,101,11111,91,1111111,10001,1001001,9091,11111111111,9901, %T A019328 1111111111111,909091,90090991,100000001,11111111111111111,999001, %U A019328 1111111111111111111,99009901,900900990991,9090909091,11111111111111111111111,99990001 %N A019328 Cyclotomic polynomials at x=10. %C A019328 See A138940 for indices n for which a(n) is prime. - _M. F. Hasler_, Jan 09 2015 %H A019328 Paolo Xausa, <a href="/A019328/b019328.txt">Table of n, a(n) for n = 1..900</a> %H A019328 <a href="/index/Cy#CyclotomicPolynomialsValuesAtX">Index entries for cyclotomic polynomials, values at X</a> %p A019328 with(numtheory,cyclotomic); f := n->subs(x=10,cyclotomic(n,x)); seq(f(i),i=0..64); %t A019328 Cyclotomic[Range[30], 10] (* _Paolo Xausa_, Feb 26 2024 *) %o A019328 (PARI) A019328(n)=polcyclo(n,10) \\ Simplified by _M. F. Hasler_, Jan 09 2015 %K A019328 nonn %O A019328 1,1 %A A019328 _Simon Plouffe_