A143799 Lesser of Twin prime numbers of the form : i^2+j^3, as sum of square and cube, if Greater Twin prime number also of the form : i^2+j^3, as sum of square and cube.

827, 1049, 3257, 4967, 11159, 17207, 23831, 31319, 31391, 49391, 53279, 60761, 63647, 68207, 74201, 78191, 82007, 92177, 110567, 110879, 124247, 132047, 136067, 136601, 176777, 181889, 204791, 234977, 245897, 291689, 343391, 345887, 358289

Offset

1,1

Links

Table of n, a(n) for n=1..33.

Example

827=22^2+7^3, 829=9^3+10^2; 1049=7^2+10^3, 1051=32^2+3^3; 3257=57^2+2^3, 3259=54^2+7^3;

Mathematica

lst1={}; For[i=1, i<=11^3, For[j=1, j<=11^3, c=i^2+j^3; If[((PrimeQ[c]&&PrimeQ[c-2])||(PrimeQ[c]&&PrimeQ[c+2])), AppendTo[lst1, c]]; j++ ]; i++ ]; lst2=Take[Union[lst1], 4*10^3]; lst3={}; For[k=2, k<Length[lst2], v=Take[lst2, {k-1}][[1]]; w=Take[lst2, {k}][[1]]; x=w-v; If[x==2, AppendTo[lst3, v]]; k++ ]; lst3

Crossrefs

Sequence in context: A251611 A104375 A066946 * A046496 A102350 A108830

Adjacent sequences: A143796 A143797 A143798 * A143800 A143801 A143802

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Sep 01 2008

Status

approved