23989

Appears in sequences

• Numbers k such that k, k+1, k+2 and k+3 have the same number of divisors.at n=33A006601
• Sum of next n composite numbers.at n=33A072475
• Starting positions of strings of three 9's in the decimal expansion of Pi.at n=27A083642
• Riordan array (1/(1 + 5*x + x^2), x/(1 + 5*x + x^2))^(-1); inverse of Riordan array A123967.at n=31A125906
• Numbers that appear exactly five times in A101402. (Also indices of fives in A101403.).at n=16A129117
• Number of (n+2) X 3 binary arrays with each 3 X 3 subblock having rows and columns in lexicographically nondecreasing order.at n=41A184540
• Composite numbers k such that sigma(k + sigma(k)) = 2*sigma(k).at n=26A246858
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(n) - 1, where a(0) = 3, a(1) = 4, b(0) = 1, b(1) = 2, b(2) = 5, and (a(n)) and (b(n)) are increasing complementary sequences.at n=17A295962
• MM-numbers of labeled graphs with loops spanning an initial interval of positive integers.at n=30A320461
• Record values in A356640.at n=16A356642