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 A382725 #15 Aug 17 2025 07:59:37 %S A382725 1,2,3,4,5,6,7,8,5,10,9,12,11,14,14,16,5,10,13,20,13,18,20,24,11,22, %T A382725 20,28,22,28,28,32,5,10,13,20,17,26,28,40,13,26,26,36,28,40,40,48,11, %U A382725 22,28,44,28,40,44,56,22,44,40,56,44,56,56,64,5,10,13,20,17,26,28,40,17,34,34,52,36,56,56,80,13 %N A382725 Number of entries in the n-th row of Pascal's triangle not divisible by 8. %H A382725 James G. Huard, Blair K. Spearman, and Kenneth S. Williams, <a href="https://doi.org/10.1006/eujc.1997.0146">Pascal's triangle (mod 8)</a>, European Journal of Combinatorics 19:1 (1998), pp. 45-62. %o A382725 (Python) %o A382725 def A382725(n): %o A382725 n1 = n>>1 %o A382725 n2 = n1>>1 %o A382725 np = ~n %o A382725 n100 = (n2&(~n1)&np).bit_count() %o A382725 n110 = (n2&n1&np).bit_count() %o A382725 n10 = (n1&np).bit_count() %o A382725 return ((n100+1<<3)+(n110<<1)+n10*(n10+3))<<n.bit_count()>>3 # _Chai Wah Wu_, Aug 10 2025 %Y A382725 Cf. A001316, A006047, A194459, A382720-A382724. %K A382725 nonn,changed %O A382725 0,2 %A A382725 _N. J. A. Sloane_, Apr 23 2025