A181882 The sums of pairs of adjacent terms are the odd palindromic primes in ascending order.

2, 1, 4, 3, 8, 93, 38, 113, 68, 123, 190, 163, 210, 173, 554, 203, 584, 213, 706, 223, 10078, 423, 10178, 1133, 10278, 2143, 10578, 2243, 11088, 2743, 11188, 3153, 11588, 3863, 11688, 4373, 11988, 4573, 12088, 5383, 12588, 5593

Offset

1,1

Comments

This sequence was originally presented at http://www.sanaristikot.net by V.J. Pohjola, Nov 11 2010. [Added by V.J. Pohjola, Nov 25 2010.]

There are four possible solutions: see A181881-A181884.

Links

Table of n, a(n) for n=1..42.

V. J. Pohjola, a(n)+a(n+1) = palindromic prime, Posting to the Sequence Fans Mailing List, Nov 11 2010.

Mathematica

lst = {}; a = 2; c = 0; Label[alku1]; b = c; Label[alku2]; b =b + 1; If[PrimeQ[a + b] && IntegerDigits[a + b] == Reverse[IntegerDigits[a + b]], AppendTo[lst, a], Goto[alku2]]; c = a; a = b; If[a < nn, Goto[alku1]]; lst  (* V.J. Pohjola, Nov 25 2010 *)
a[1] = 2; pp = Select[Prime[Range[3000]], PalindromeQ]; lp = Length[pp]-1;
aa = Table[a[n] + a[n+1], {n, lp}]; Array[a, lp] /. Solve[Thread[aa == Rest[pp]]][[1]] (* Jean-François Alcover, Feb 17 2018 *)

Crossrefs

Cf. A002385, A181881, A181883, A181884.

Sequence in context: A262230 A262155 A355166 * A109195 A258310 A217927

Adjacent sequences: A181879 A181880 A181881 * A181883 A181884 A181885

Keyword

nonn,easy,base

Author

N. J. A. Sloane, Nov 18 2010

Extensions

More terms from Nathaniel Johnston, Nov 22 2010

Status

approved