24753
domain: N
Appears in sequences
- Numbers k such that k | 11^k + 1.at n=22A015960
- Numbers k such that k!!! + 1 is prime (0 is included by convention).at n=41A037083
- Triangular numbers with sum of digits = 21.at n=19A068131
- Products of members of pairs in A075333.at n=38A075337
- Triangular numbers which are also happy numbers (cf. A007770).at n=34A076712
- Third row of Pascal-(1,6,1) array A081581.at n=32A081591
- a(n) = smallest k where (10^k+1)=0 mod prime(n)^2, or 0 if no such k exists.at n=47A086981
- Triangular numbers with palindromic indices.at n=31A089717
- Triangular numbers whose digit reversal is the product of 2 palindromes greater than 1.at n=29A115702
- Triangular numbers for which the sum of the digits is an octagonal number.at n=22A117523
- Numbers k such that k^3 divides 11^(k^2) + 1.at n=3A128684
- Triangular numbers T such that T+10 is the next prime after T.at n=6A129540
- Triangular numbers t such that t+10 is a prime.at n=30A129755
- a(n) = 3*n*(6*n + 1).at n=37A144314
- Triangular numbers of the form 2p-1 where p is prime.at n=30A217000
- Triangular numbers which are an average of four consecutive primes.at n=22A226196
- Triangular numbers which have one or more occurrences of exactly five different digits.at n=15A241788
- Triangular numbers T such that both (T+2) and (T-2) are semiprimes.at n=29A242356
- Numbers k such that k^2 divides 11^k + 1.at n=3A292336
- a(n) = Sum_{k=0..n} binomial(k, 6*(n-k)).at n=19A293169