A108660 Square-loop primes.

2, 13, 31, 79, 97, 227, 881, 1013, 2797, 3181, 3631, 8101, 22727, 81001, 101363, 109013, 131363, 181813, 272227, 310181, 310901, 318181, 318881, 631013, 636313, 810401, 818101, 901097, 904097, 972227, 1018813, 1090013, 1810013, 2272727

Offset

1,1

Comments

Primes such that each pair of adjacent digits (and also the first and the last ones) sums up to a square. First term is arguable since there is 'no pair of adjacent digits', but there are the "first" and "last" digits.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..120

Mathematica

Select[Prime[Range[200000]], And@@(IntegerQ[Sqrt[#]]&/@(Total/@Partition[ IntegerDigits[#], 2, 1, 1]))&] (* Harvey P. Dale, Mar 03 2014 *)

Crossrefs

Cf. A046704, A007953, A088133, A088134, A088135, A088136, A108659.

Sequence in context: A158720 A108659 A086924 * A107132 A106959 A285096

Adjacent sequences: A108657 A108658 A108659 * A108661 A108662 A108663

Keyword

nonn,base

Author

Zak Seidov, Jun 16 2005

Status

approved