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A169669 (first digit of n) * (last digit of n) in decimal representation. 4
0, 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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

a(n) = A000030(n)*A010879(n);

a(n) = A115300(n) for n<=100, A115300(101) = 0;

a(n) = A111707(n) for n<=109, A111707(110) = 1;

0 <= a(n) <= 81, range = A174995;

a(10*n + n mod 10) = a(n);

a(A008592(n)) = 0;

A000030(a(A017281(n))) = A000030(A017281(n));

a(n) = a(A004086(n))*A168184(n);

LINKS

R. Zumkeller, Table of n, a(n) for n = 0..10000

PROG

(Haskell)

a169669 n = a000030 n * mod n 10

-- Reinhard Zumkeller, Apr 29 2015

CROSSREFS

A088133.

Cf. A000030, A008592, A010879, A111707, A115300, A174995.

Sequence in context: A292678 A072595 A334832 * A111707 A115300 A085942

Adjacent sequences:  A169666 A169667 A169668 * A169670 A169671 A169672

KEYWORD

base,nonn,hear,look

AUTHOR

Reinhard Zumkeller, Apr 05 2010

STATUS

approved

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Last modified December 2 18:09 EST 2021. Contains 349445 sequences. (Running on oeis4.)