A072386 Primes which can be represented as the sum of a triangular number and its reverse.

2, 11, 281, 21701, 42923, 72227, 73037, 78887, 79697, 100109, 119891, 122321, 128981, 138683, 178697, 1360631, 1394831, 1591841, 1598951, 1607051, 1958591, 1982891, 2188811, 2401031, 2490941, 2793071, 3382733, 3555443, 3586853

Offset

1,1

Links

Table of n, a(n) for n=1..29.

Example

11 is a term because it is prime and it is the sum of triangular number 10 and its reverse 01.

Mathematica

Take[Select[Union[#+IntegerReverse[#]&/@Accumulate[Range[ 5000]]], PrimeQ], 30] (* Requires Mathematica version 10 or later *)  (* Harvey P. Dale, Aug 29 2016 *)

Crossrefs

Sequence in context: A132571 A102031 A248865 * A185122 A350932 A369947

Adjacent sequences: A072383 A072384 A072385 * A072387 A072388 A072389

Keyword

base,nonn

Author

Shyam Sunder Gupta, Jul 20 2002

Status

approved