26467

Appears in sequences

• Pseudoprimes to base 11.at n=42A020139
• Strong pseudoprimes to base 12.at n=18A020238
• Strong pseudoprimes to base 27.at n=25A020253
• (Prime(prime(n))^2-1)/24.at n=32A092772
• Pentagonal numbers (A000326) whose digit reversal is a semiprime (A001358).at n=39A115709
• Numbers which are both lucky and pentagonal.at n=12A128511
• Numbers m such that k = m*23^2 divides 3^(k-1) - 2^(k-1).at n=15A130058
• Number of distinct values of the sum of 3 products of three 0..n integers.at n=21A225260
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 382", based on the 5-celled von Neumann neighborhood.at n=39A271541
• Numbers k such that 3^(k-1) == 2^(k-1) !== 1 (mod k).at n=30A285300
• A digitized pure tuning tone, sampled at standard settings for consumer audio: a(n) = floor(sin(2*Pi*(440/44100)*n)*32767).at n=15A320277
• a(n) = Sum_{i=1..n, j=1..n, gcd(i,j)=2} (n+1-i)*(n+1-j).at n=27A331761
• Pentagonal numbers which are products of three distinct primes.at n=29A381650
• Expansion of (1/x) * Series_Reversion( x / ((1+x)^4 * (x+(1+x)^4)) ).at n=4A388732