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 A382722 #11 Aug 10 2025 12:12:11 %S A382722 1,2,3,4,5,6,7,8,9,10,11,12,13,2,4,6,8,10,12,14,16,18,20,22,24,26,3,6, %T A382722 9,12,15,18,21,24,27,30,33,36,39,4,8,12,16,20,24,28,32,36,40,44,48,52, %U A382722 5,10,15,20,25,30,35,40,45,50,55,60,65,6,12,18,24,30,36,42,48,54,60,66,72,78,7,14,21 %N A382722 Number of entries in the n-th row of Pascal's triangle not divisible by 13. %H A382722 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 A382722 (Python) %o A382722 from math import prod %o A382722 from gmpy2 import digits %o A382722 def A382722(n): return prod(int(d,13)+1 for d in digits(n,13)) # _Chai Wah Wu_, Aug 10 2025 %Y A382722 Cf. A001316, A006047, A194459, A382720-A382721. %K A382722 nonn %O A382722 0,2 %A A382722 _N. J. A. Sloane_, Apr 23 2025