

A069496


Smaller member of a twin prime pair with a square sum.


13



17, 71, 881, 1151, 2591, 3527, 4049, 15137, 20807, 34847, 46817, 69191, 83231, 103967, 112337, 149057, 176417, 179999, 206081, 281249, 362951, 388961, 438047, 472391, 478241, 538721, 649799, 734471, 808991, 960497, 1080449, 1143071
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OFFSET

1,1


COMMENTS

All members of this sequence have digital root 8.  J. W. Helkenberg, Jul 24 2013
First bisection of A232878.  Gary Croft, Dec 05 2013


LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000
Author?, Title? (no longer exists)


FORMULA

a(n) = (A037072(n)2)/2.
a(n) = A118593(n)  2.  Zerinvary Lajos, Jul 31 2006


EXAMPLE

71 is a term as the smaller member of the twin prime pair (71,73) as 71+73 = 144 = 12^2.


MATHEMATICA

First/@Select[Partition[Prime[Range[9*10^4]], 2, 1], Differences[#]=={2} && IntegerQ[Sqrt[Total[#]]] &] (* Jayanta Basu, May 26 2013 *)


PROG

(PARI) t(n, p=3) = {while( p+2 < (p=nextprime( p+1 ))  n>0, ); p2}
for(n=1, 1e4, if(issquare(2*t(n)+2), print1(t(n), ", "))); \\ Altug Alkan, Mar 14 2016


CROSSREFS

Cf. A118593, A232878.
Sequence in context: A290243 A320895 A288748 * A047978 A050524 A214530
Adjacent sequences: A069493 A069494 A069495 * A069497 A069498 A069499


KEYWORD

nonn


AUTHOR

Amarnath Murthy, Mar 30 2002


EXTENSIONS

More terms from Sascha Kurz, Apr 01 2002


STATUS

approved



