login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A109880 Numbers n such that n and its digit reversal both are difference of successive cubes. 1
1, 7, 19, 91, 127, 721, 919, 14491, 19441, 113491, 177877, 194311, 778771, 1081801, 1188811, 1767169, 1927207, 1946491, 7027291, 9617671, 16056847, 74775169, 74865061, 96157747, 129869461, 164968921, 167828761, 180676081, 189202267, 757333297, 762202981, 792333757, 1917766117, 7116677191 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A subsequence of A109879.

LINKS

Table of n, a(n) for n=1..34.

EXAMPLE

19 = 3^3-2^3 and 91 = 6^3-5^3.

MATHEMATICA

okQ[x_]:=Module[{revx=FromDigits[Reverse[IntegerDigits[x]]]}, And@@(And@@IntegerQ/@(n/.Solve[1+3n+3n^2==x, n])&&And@@IntegerQ/@(n/.Solve[1+3n+3n^2==revx, n]))] Select[Range[90000], okQ] - Harvey P. Dale, Aug 06 2007

CROSSREFS

Cf. A109879.

Sequence in context: A267378 A088988 A109879 * A245489 A084603 A088883

Adjacent sequences:  A109877 A109878 A109879 * A109881 A109882 A109883

KEYWORD

base,nonn

AUTHOR

Amarnath Murthy, Jul 10 2005

EXTENSIONS

More terms from Harvey P. Dale, Aug 06 2007

23 more terms from Donovan Johnson, Feb 21 2008

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 12 18:03 EDT 2020. Contains 335666 sequences. (Running on oeis4.)