18871

Appears in sequences

• Decimal part of n-th root of a(n) starts with digit 2.at n=52A034079
• Number of planar graphs with n nodes and chromatic number 2.at n=9A164099
• Totally multiplicative sequence with a(p) = a(p-1) + 6 for prime p.at n=40A166703
• The largest number m such that sigma(m) = A007368(n), where A007368(n) = the smallest k such that sigma(x) = k has exactly n solutions.at n=39A184394
• Numbers obtained by alternatively adding centered pentagonal layers of 5*(2^n-1) and 5*(3^n-1) elements.at n=15A276917
• Numbers n for which A326073(n) is equal to abs(1+A326146(n)).at n=15A326074
• Index where prime(n) appears as a term in A379248.at n=47A379290