A115299 Greatest digit of n + least digit of n. Different from A088133.

2, 4, 6, 8, 10, 12, 14, 16, 18, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 8, 9, 10, 11, 12, 13, 14

Offset: 1

Author

Rick L. Shepherd, Jan 20 2006

Keywords

• base
• nonn

Comments

a(101) = 1 and A088133(101) = 2, but all previous terms match.

Examples

			a(1) = 1 + 1 = 2, a(232) = 3 + 2 = 5, a(1889009898) = 9 + 0 = 9.
		

Links

• Michael S. Branicky, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A037904 (greatest-least), A115300 (greatest*least), A088133 (first+last).

Programs

Mathematica

Array[Max[#] + Min[#] &@ IntegerDigits[#] &, 120] (* Michael De Vlieger, Dec 12 2023 *)

Python

def a(n): d = list(map(int, str(n))); return max(d) + min(d)
print([a(n) for n in range(1, 87)]) # Michael S. Branicky, Dec 12 2023