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A121947 Positive numbers that are sums of proper substrings of their reversals. 1
149, 198, 1392, 16041957, 10000000009, 132324898229, 154879506575, 14501949763339, 15509886785307493, 16314428059046884, 1589868655913263939 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(12) > 10^20. - Jon E. Schoenfield, Nov 15 2013

LINKS

Table of n, a(n) for n=1..11.

EXAMPLE

149 is in the sequence because 149 = 1 + 4 + 9 + 41 + 94.

MATHEMATICA

Select[Table[ n, {n, 10000000}], # == Plus @@ ToExpression[ Flatten[Table[ StringTake[StringReverse[ToString[ # ]], {i, j}], {i, StringLength[ToString[ # ]]}, {j, i, StringLength[ToString[ # ]]}]]] - ToExpression[StringReverse[ToString[ # ]]] &]

CROSSREFS

Cf. A121535.

Sequence in context: A209619 A031929 A161487 * A141946 A128390 A142029

Adjacent sequences:  A121944 A121945 A121946 * A121948 A121949 A121950

KEYWORD

base,more,nonn

AUTHOR

Tanya Khovanova, Sep 04 2006

EXTENSIONS

a(4) from Donovan Johnson, Mar 30 2010

a(5) from Jon E. Schoenfield, Nov 12 2013

a(6) - a(11) from Jon E. Schoenfield, Nov 13 2013

STATUS

approved

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Last modified April 25 08:38 EDT 2017. Contains 285348 sequences.