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A081553 Sum of n-th row of A081551. 2
1, 21, 303, 4006, 50010, 600015, 7000021, 80000028, 900000036, 1000000045, 10000000055, 100000000066 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..12.

FORMULA

a(n) = n*10^(n-1) + n(n-1)/2.

CROSSREFS

Cf. A081551, A081552.

Sequence in context: A079517 A021784 A019618 * A021524 A021268 A018069

Adjacent sequences:  A081550 A081551 A081552 * A081554 A081555 A081556

KEYWORD

base,easy,nonn

AUTHOR

Amarnath Murthy, Apr 01 2003

STATUS

approved

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Last modified December 5 11:41 EST 2016. Contains 278764 sequences.