40186

Appears in sequences

• Even triangular numbers with prime indices.at n=31A034955
• Numbers k such that 273*2^k-1 is prime.at n=42A050895
• a(n) = 49*(n*(n+1)/2) + 6.at n=40A061792
• Triangular numbers whose digit permutations yield at least two further triangular numbers.at n=23A069674
• Sort the digits of these triangular numbers into descending order and drop zeros to get primes.at n=35A082923
• Antidiagonal sums of triangle A092422, which is generated from the even-numbered Fibonacci polynomials (A011973).at n=19A092424
• Triangular numbers all of whose digits are nonprimes.at n=27A111484
• a(n) = {n^2}_{n^2}.at n=13A122626
• Hexagonal numbers (A000384) which are sum of 2 other hexagonal numbers > 0.at n=31A133215
• Number of days after Jan 01 1000 such that the date written in the ISO-8601-format YYYYMMDD is palindromic.at n=13A210883
• Triangular numbers which have one or more occurrences of exactly five different digits.at n=29A241788
• Numbers k such that 4 is the smallest decimal digit of k^3.at n=39A291643
• Squares where A323810 gets stuck.at n=10A323814
• Hexagonal numbers that are sphenic numbers.at n=31A380007