21373

Appears in sequences

• Number of letters in English name for n increases at these numbers.at n=33A001619
• a(n) = Sum_{j=0..n} j*Fibonacci(j).at n=15A014286
• Decimal part of n-th root of a(n) starts with digit 3.at n=36A034080
• Indices of records in length of English name of n including spaces and dashes (A052360): n such that k < n => A052360(k) < A052360(n).at n=34A052362
• The smallest magic constant for n X n magic square with prime entries (regarding 1 as a prime).at n=16A073502
• Consider the 2^n compositions of n and count only those ending in an odd part with row sum A001045.at n=9A123638
• Least natural number in English which requires exactly n characters to spell including spaces and hyphens, or 0 if no such number exists. The inverse of A052360.at n=44A132363
• Number of self-avoiding walks on cubic lattice with no more than n steps.at n=6A140476
• Numbers with d digits (d>0) which have at least 2d distinct primes as substrings.at n=15A168167
• a(n) = Smallest number which has in its English name the letter "T" in the n-th position beginning the count from the end.at n=40A173206
• Numbers k such that A334943(k) = 1.at n=17A335773
• Products of three distinct strong primes.at n=16A363782
• E.g.f. A(x) satisfies A(x) = exp(-x*A(x)^2) + x.at n=6A379856
• a(n) is the number of 5 element sets of distinct integer-sided trapezoids whose base angles are 60 degrees that fill an equilateral triangular grid of side n units without partitioning a triangle into 3 element sets of trapezoids.at n=28A391452