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A153211 Sum of digits of n, times digital reversal of sum of digits of n. 0
1, 4, 9, 16, 25, 36, 49, 64, 81, 1, 4, 9, 16, 25, 36, 49, 64, 81, 10, 4, 9, 16, 25, 36, 49, 64, 81, 10, 121, 9, 16, 25, 36, 49, 64, 81, 10, 121, 252, 16, 25, 36, 49, 64, 81, 10, 121, 252, 403, 25, 36, 49, 64, 81, 10, 121, 252, 403, 574, 36, 49, 64, 81, 10, 121, 252, 403, 574 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

The fixed points of this sequence {n such that a(n) = n} are A110921.

FORMULA

a(n) = SOD(n)*R(SOD(n)) = A007953(n)*A004086(A007953(n)).

EXAMPLE

a(19) = (1+9)*R(1+9) = 10*01 = 10*1 = 10. a(79) = 976 because (7+9)*R(7+9) = 16*61 = 976.

CROSSREFS

Cf. A004086, A007953, A110921.

Sequence in context: A003132 A062331 A069940 * A118881 A098733 A083163

Adjacent sequences:  A153208 A153209 A153210 * A153212 A153213 A153214

KEYWORD

base,easy,nonn

AUTHOR

Jonathan Vos Post (jvospost3(AT)gmail.com), Dec 20 2008

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Last modified February 15 21:56 EST 2012. Contains 205860 sequences.