A115300 Greatest digit of n * least digit of n.

1, 4, 9, 16, 25, 36, 49, 64, 81, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 0, 3, 6, 9, 12, 15, 18, 21, 24, 27, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 0, 6, 12, 18, 24, 30, 36, 42, 48, 54, 0, 7, 14, 21, 28, 35, 42, 49, 56, 63, 0, 8

Offset

1,2

Comments

a(101) = 0 and A111707(101) = 1, but all previous terms match.

a(n) = A169669(n) for n <= 100.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Formula

a(n) = A054054(n)*A054055(n). - Reinhard Zumkeller, Apr 29 2015

Example

a(3) = 3 * 3 = 9, a(232) = 3 * 2 = 6, a(1889009898) = 9 * 0 = 0.

Prog

(Haskell)
a115300 n = a054054 n * a054055 n  -- Reinhard Zumkeller, Apr 29 2015
(Python)
def a(n): d = list(map(int, str(n))); return max(d) * min(d)
print([a(n) for n in range(1, 82)]) # Michael S. Branicky, Dec 12 2023

Crossrefs

Cf. A037904 (greatest-least), A115299 (greatest+least), A111707.

Cf. A054054, A054055, A169669.

Sequence in context: A334832 A169669 A111707 * A085942 A066308 A063462

Adjacent sequences: A115297 A115298 A115299 * A115301 A115302 A115303

Keyword

base,nonn

Author

Rick L. Shepherd, Jan 20 2006

Status

approved