A063792 Subtractive primes: p = x1x2x3..xk is a k-digit prime in base 10 such that abs(x1-x2-x3-...-xk) is also a prime.

2, 3, 5, 7, 13, 29, 31, 41, 47, 53, 61, 79, 83, 97, 103, 113, 131, 139, 151, 157, 193, 199, 223, 227, 241, 263, 269, 281, 317, 337, 353, 359, 373, 379, 397, 401, 409, 433, 443, 461, 463, 487, 503, 521, 557, 571, 593, 599, 601, 613, 617, 631, 647, 653

Offset

1,1

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

Example

269 belong to the sequence because |2 - 6 - 9| = |-13| = 13.

Mathematica

okQ[n_] := Module[{idn = -1# & /@ IntegerDigits[n]}, PrimeQ[Plus @@ Rest[idn] - First[idn]]]; Select[Prime[Range[120]], okQ]

Prog

(PARI) SubD(x)= { local(s); s=0; while (x>9, s+=x-10*(x\10); x\=10); return(abs(s - x)) }
{ n=0; p=0; for (m=1, 10^9, p=nextprime(p+1); if(isprime(SubD(p)), write("b063792.txt", n++, " ", p); if (n==1000, break)) ) } \\ Harry J. Smith, Aug 31 2009

Crossrefs

Sequence in context: A346408 A158281 A115261 * A270391 A172508 A272107

Adjacent sequences: A063789 A063790 A063791 * A063793 A063794 A063795

Keyword

easy,nonn,base

Author

Felice Russo, Aug 17 2001

Extensions

Corrected by Harvey P. Dale, Aug 20 2001

Status

approved