131415

Appears in sequences

• Decimal concatenation of n, n+1, and n+2.at n=13A001703
• Let N = 123456789101112131415161718..., the concatenation of the natural numbers. a(n) is the n-digit number formed from the digits of N starting from the {n(n-1)/2 +1}th digit. Omit any leading zeros.at n=5A066547
• Duplicate of A001703.at n=13A127422
• Concatenate (3n-2,3n-1,3n).at n=4A248556
• Number of length 4+1 0..n arrays with the sum of the cubes of adjacent differences multiplied by some arrangement of +-1 equal to zero.at n=25A250231
• Solution of the complementary equation a(n) = a(n-1) + a(n-2) + b(0) + b(1) + ... + b(n-1), where a(0) = 1, a(1) = 2, b(0) = 3, and (a(n)) and (b(n)) are increasing complementary sequences.at n=19A295053
• a(n) = Sum_{p|n, p prime} p^prime(n/p).at n=13A369750