The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A086042 Nontrivial numbers which are prime and yield another prime when their digits are sorted in ascending order. 3
 31, 71, 73, 97, 101, 103, 107, 109, 131, 173, 193, 197, 271, 293, 307, 311, 317, 373, 397, 419, 439, 491, 509, 547, 571, 593, 607, 617, 647, 659, 673, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 809, 839, 907, 919, 937, 941, 947, 953, 971, 983, 991 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Primes with digits already in ascending order (like 13 and 2357) are trivial cases and are therefore excluded. See A211654 for the sequence including the trivial cases. - M. F. Hasler, Jul 30 2019 LINKS Harvey P. Dale, Table of n, a(n) for n = 1..1000 EXAMPLE a(1)=31 because an ascending sort of 31's digits yields 13 which is also prime. a(53)=1009 because an ascending sort of 1009's digits yields 19 which is also prime. MATHEMATICA paoQ[n_]:=Module[{idn=IntegerDigits[n], sidn}, sidn=Sort[idn]; sidn!=idn && PrimeQ[FromDigits[sidn]]] (* Harvey P. Dale, Nov 14 2011 *) PROG (PARI) select( is_A086042(p, q=fromdigits(vecsort(digits(p))))={p>q&&isprime(q)&&isprime(p)}, [1..999]) \\ M. F. Hasler, Jul 30 2019 (MAGMA) [p:p in PrimesUpTo(1000)|  IsPrime(Seqint(Reverse(Sort(Intseq(p, 10))))) and p ne Seqint(Reverse(Sort(Intseq(p, 10)))) ]; // Marius A. Burtea, Jul 30 2019 CROSSREFS Cf. A086402, A086051, A211654. Sequence in context: A110831 A212723 A193573 * A086051 A109309 A263242 Adjacent sequences:  A086039 A086040 A086041 * A086043 A086044 A086045 KEYWORD base,nonn AUTHOR Chuck Seggelin (barkeep(AT)plastereddragon.com), Jul 07 2003 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 18 03:46 EDT 2021. Contains 345098 sequences. (Running on oeis4.)