

A121535


Numbers that are sums of substrings of their reversals.


1



1, 2, 3, 4, 5, 6, 7, 8, 9, 54, 271, 7846, 937767, 605772815, 87246282837, 547880799393, 2399113322502, 4137547470482, 45252394397843, 1531558595686560, 1281758695960501, 2008670909471090, 3385200300351842, 6108670309471325, 7985400400619556, 8253670509407076
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OFFSET

1,2


COMMENTS

a(16) <= 547880799393. [From Donovan Johnson, May 25 2009]


LINKS

Table of n, a(n) for n=1..26.


EXAMPLE

For example: 54 = 45 + 4 + 5; 271 = 172 + 17 + 72 + 1 + 7 + 2.


MATHEMATICA

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


CROSSREFS

Cf. A121947  Numbers that are sums of proper substrings of their reversals.
Sequence in context: A327735 A133287 A133377 * A082743 A083838 A087082
Adjacent sequences: A121532 A121533 A121534 * A121536 A121537 A121538


KEYWORD

base,nonn


AUTHOR

Tanya Khovanova, Sep 08 2006


EXTENSIONS

a(14)a(15) from Donovan Johnson, May 25 2009
More terms from Jon E. Schoenfield, Nov 15 2013


STATUS

approved



