72490

Appears in sequences

• Number of n-celled polyominoes without holes, symmetric about axis 2.at n=41A056880
• Pentagonal numbers for which the sum of the digits is also a pentagonal number.at n=25A117709
• Pentagonal numbers for which both the sum of the digits and the product of the digits are pentagonal numbers.at n=15A117711
• Triangle T(n,k), n>=0, 0<=k<=C(n,2), read by rows: T(n,k) = number of k-length chains in the poset of Dyck paths of semilength n ordered by inclusion.at n=28A193629
• Triangle T(n,k) read by rows: coefficients of polynomials P_n(t) defined in Formula section.at n=59A287030
• Pentagonal numbers which are products of four distinct primes.at n=35A381919