147258

Appears in sequences

• Number of partitions of n minus the number of primes <= n.at n=47A183151
• Numbers k having at least two complementary pairs of divisors (q, p) and (p', q') such that k = p*q = p'*q' where the decimal digits of p' are the 9's complement of the decimal digits of p and the decimal digits of q' are the 9's complement of the decimal digits of q.at n=25A226587
• Heptagonal numbers (A000566) in which parity of digits alternates.at n=24A297646
• Numbers k whose bi-unitary divisors have an even sum which is larger than 2k, but they cannot be partitioned into two disjoint parts whose sums are equal.at n=14A323342
• a(n) is the least number k such that the sequence of elements of the abundancy index of k is palindromic with length n, or -1 if no such k exists.at n=9A349689