login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A028348 Numbers n such that n^2 + 3*n + 1 is a palindrome. 1
1, 2, 6, 10, 12, 21, 29, 35, 94, 100, 117, 122, 325, 380, 442, 1000, 1132, 1307, 3073, 10000, 10325, 10602, 12652, 13207, 30404, 30834, 31474, 32672, 95603, 96439, 100000, 110665, 234566, 236026, 308863, 709781, 987443, 1000000, 1060602, 1099265, 1172835 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..41.

P. De Geest, Palindromic Quasi_Under_Squares of the form n+(n+1)^2

MATHEMATICA

palQ[n_]:=Module[{id=IntegerDigits[n^2+3n+1]}, id==Reverse[id]]; Select[Range[240000], palQ] (* From Harvey P.Dale, Apr 17 2012 *)

CROSSREFS

Cf. A028349.

Sequence in context: A263309 A190789 A071638 * A214963 A140776 A277238

Adjacent sequences:  A028345 A028346 A028347 * A028349 A028350 A028351

KEYWORD

nonn,base

AUTHOR

Patrick De Geest

EXTENSIONS

Extended and definition corrected by T. D. Noe, Apr 17 2012

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 | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified September 24 04:27 EDT 2017. Contains 292403 sequences.