1352569
domain: N
Appears in sequences
- a(n) = prime^2 and digits of prime appear in a(n).at n=25A030081
- Numbers k that require four iterations of the sigma function to be >= 2*k.at n=21A107914
- Odd numbers N for which numerator(sigma(N)/N) is a prime.at n=34A193065
- Number of n X 2 0..3 arrays with rows, antidiagonals and columns unimodal.at n=6A223756
- Number of nX7 0..3 arrays with rows, antidiagonals and columns unimodal.at n=1A223761
- T(n,k)=Number of nXk 0..3 arrays with rows, antidiagonals and columns unimodal.at n=29A223762
- T(n,k)=Number of nXk 0..3 arrays with rows, antidiagonals and columns unimodal.at n=34A223762
- Number of nX7 0..3 arrays with rows and antidiagonals unimodal.at n=1A223800
- T(n,k)=Number of nXk 0..3 arrays with rows and antidiagonals unimodal.at n=29A223801
- T(n,k)=Number of nXk 0..3 arrays with rows, columns, diagonals and antidiagonals unimodal.at n=29A223811
- T(n,k)=Number of nXk 0..3 arrays with rows, columns, diagonals and antidiagonals unimodal.at n=34A223811
- Number of nX7 0..3 arrays with rows and columns unimodal.at n=1A223849
- T(n,k)=Number of nXk 0..3 arrays with rows and columns unimodal.at n=29A223850
- T(n,k)=Number of nXk 0..3 arrays with rows and columns unimodal.at n=34A223850
- Number of nX7 0..3 arrays with rows, diagonals and antidiagonals unimodal.at n=1A223875
- T(n,k)=Number of nXk 0..3 arrays with rows, diagonals and antidiagonals unimodal.at n=29A223876
- Numbers k such that tau(sigma(tau(k))) = sigma(tau(sigma(k))), where tau is A000005 and sigma is A000203.at n=29A237613
- Numbers n such that 2n-1 and sigma(n) are both primes.at n=20A249902
- Odd numbers with prime sum of divisors.at n=32A278911
- Numbers k for which A348717(k) is a multiple of A348717(sigma(k)).at n=45A364131