21148

Appears in sequences

• Number of partitions of n into at most 1 copy of 1, 2 copies of 2, 3 copies of 3, ... .at n=48A052335
• First of triples of consecutive happy numbers, i.e., the first of three consecutive integers each of which is a happy number (A007770).at n=21A072494
• phi(n) plus the n-th prime gives a square.at n=38A116021
• First of quadruples of consecutive happy numbers.at n=4A194352
• Triangle read by rows: T(n,k) gives the number of ballot sequences of length n having exactly k descents, n>=0, 0<=k<=n.at n=80A238121
• Irregular triangle read by rows: T(n,k) gives the number of ballot sequences of length n having k descents, n>=0, 0<=k<=A083920(n-1).at n=45A238122
• Number of ballot sequences of length n having exactly two descents.at n=7A241795
• Numbers for which the cube of the sum of the digits is equal to the square of the product of their digits.at n=28A241846
• Sum of quadratic residues of (n-th prime == 3 mod 4).at n=33A282035
• Let p = n-th prime == 7 mod 8; a(n) = sum of quadratic residues mod p.at n=16A282041
• Partial sums of A299896.at n=35A299897
• Number of binary words of length n with all distinct runs.at n=20A351016