A111349 Numbers n such that the result of swapping the 4th digit and the digit 3 positions from the last digit is prime.

1003, 1004, 1007, 1009, 1010, 1012, 1013, 1015, 1016, 1018, 1019, 1021, 1024, 1025, 1030, 1031, 1040, 1043, 1049, 1051, 1054, 1055, 1060, 1061, 1063, 1070, 1082, 1085, 1088, 1091, 1094, 1096, 1099, 1100, 1105, 1106, 1108, 1112, 1114, 1118, 1123, 1126

Offset

1,1

Comments

Leading zeros are dropped.

Since these numbers are just digit permutations of the primes the sequence is obviously infinite. - Charles R Greathouse IV, Oct 20 2008

Links

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

Prog

(PARI) swapn(n, d) = \ d is the digit position to swap { local(j, ln, x, s, y, y2, tmp); for(x=10^(d-1), 10^(d-1)+n, s = Str(x); ln = length(s); y = eval(Vec(s)); tmp=y[d]; y[d]=y[ln-d+1]; y[ln-d+1]=tmp; y2=0; for(j=1, ln, y2+=y[j]*10^(ln-j); ); if(isprime(y2), print1(x", ")) ) }

Crossrefs

Cf. A095179, A111347, A111348.

Sequence in context: A213316 A169828 A151956 * A182935 A350692 A013686

Adjacent sequences: A111346 A111347 A111348 * A111350 A111351 A111352

Keyword

easy,nonn,base

Author

Cino Hilliard, Nov 05 2005

Status

approved