A090933 Primes such that most significant digit swapped with all other digits yields primes.

2, 3, 5, 7, 11, 13, 17, 31, 37, 71, 73, 79, 97, 101, 107, 113, 131, 149, 167, 179, 181, 191, 199, 311, 337, 373, 389, 701, 709, 727, 733, 739, 751, 757, 787, 797, 907, 919, 937, 941, 953, 991, 1009, 1013, 1031, 1049, 1051, 1091, 1123, 1181, 1319, 1321, 1381

Offset

1,1

Comments

Appears to be denser than A090934, where the least significant digit is swapped.

Links

Table of n, a(n) for n=1..53.

Example

149 is a term as 149, 419 & 491 are all prime.

Mathematica

fQ[n_] := Block[{a = c = IntegerDigits[n], b = {}, l = Floor[ Log[10, n] + 1]}, Do[ a = c; {a[[1]], a[[i]]} = {a[[i]], a [[1]]}; AppendTo[b, FromDigits[a]], {i, 1, l}]; Union[ PrimeQ[b]] == {True}]; Select[ Prime[ Range[ 270]], fQ[ # ] &] (* Ed Pegg Jr, Jan 15 2004 *)

Crossrefs

Cf. A090934.

Sequence in context: A359139 A069706 A007500 * A107845 A234901 A090934

Adjacent sequences: A090930 A090931 A090932 * A090934 A090935 A090936

Keyword

base,nonn

Author

Amarnath Murthy, Dec 29 2003

Extensions

Edited, corrected and extended by Robert G. Wilson v, Jan 15 2004

Status

approved