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 A382721 #11 Aug 10 2025 14:09:42 %S A382721 1,2,3,4,5,6,7,8,9,10,11,2,4,6,8,10,12,14,16,18,20,22,3,6,9,12,15,18, %T A382721 21,24,27,30,33,4,8,12,16,20,24,28,32,36,40,44,5,10,15,20,25,30,35,40, %U A382721 45,50,55,6,12,18,24,30,36,42,48,54,60,66,7,14,21,28,35,42,49,56,63,70,77,8,16,24,32 %N A382721 Number of entries in the n-th row of Pascal's triangle not divisible by 11. %H A382721 Hsien-Kuei Hwang, Svante Janson, and Tsung-Hsi Tsai, <a href="https://arxiv.org/abs/2408.06817">Periodic minimum in the count of binomial coefficients not divisible by a prime</a>, arXiv:2408.06817 [math.NT], 2024. %o A382721 (Python) %o A382721 from math import prod %o A382721 from gmpy2 import digits %o A382721 def A382721(n): return prod(int(d,11)+1 for d in digits(n,11)) # _Chai Wah Wu_, Aug 10 2025 %Y A382721 Cf. A001316, A006047, A194459, A382720-A382722. %K A382721 nonn %O A382721 0,2 %A A382721 _N. J. A. Sloane_, Apr 23 2025