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

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A227856 Sequence of pairs k,g with k<3*2^n the smallest such that 3*2^n+k, 3*2^n+k+g, 3*2^n+k+2*g are three consecutive primes in arithmetic progression starting at n=5 as there is not any solution for n<5 1
 55, 6, 7, 12, 173, 6, 173, 6, 205, 6, 229, 6, 113, 6, 203, 6, 95, 6, 475, 6, 163, 6, 119, 12, 377, 18, 1045, 6, 133, 12, 551, 24, 131, 12, 259, 6, 1105, 42, 539, 6, 1487, 18, 1295, 12, 5, 12, 289, 36, 311, 36, 269, 6, 2833, 6, 1813, 18, 835, 6, 319, 6, 587, 6, 239, 30, 1225, 6, 1825, 12, 973, 12, 89, 30, 551, 12, 1805, 30, 1039, 18, 1219, 6 (list; graph; refs; listen; history; text; internal format)
 OFFSET 5,1 COMMENTS The ratio k/n^2 is in average near 0.8 and < 7 for n<701. The ratio g/n^2 is in average near 0.5 and < 4 for n<701. If 3*2^n+k > 10^22 the numbers are probable primes. LINKS Pierre CAMI, Table of n, a(n) for n = 5..1396 EXAMPLE 3*2^5+55=151, 3*2^5+55+6=157 3*2^5+55*2*6=163 151, 157, 163 three consecutive primes in arithmetic progression 6, so first pair is 55, 6 PROG PFGW & SCRIPTIFY SCRIPT DIM i DIM j DIM k DIM n, 4 DIM pp DIM qq DIM rr DIMS t OPENFILEOUT myf, a(n).txt LABEL loop1 SET n, n+1 SET i, -1 SET j, 0 SET k, 0 LABEL a SET i, i+2 SETS t, %d, %d\,; n; i SET pp, 3*2^n+i PRP pp, t IF ISPRP THEN GOTO b GOTO a LABEL b SET j, j+2 SETS t, %d, %d, %d\,; n; i; j SET qq, pp+j PRP qq, t IF ISPRP THEN GOTO c GOTO b LABEL c SET k, k+2 SETS t, %d, %d, %d, %d\,; n; i; j; k SET rr, qq+k PRP rr, t IF ISPRP THEN GOTO d GOTO c LABEL d IF j==k THEN GOTO x SET i, i+j SET pp, qq SET j, 0 SET k, 0 GOTO b LABEL x WRITE myf, t GOTO loop1 CROSSREFS Cf. A230699, A230852 Sequence in context: A159732 A174946 A182119 * A057965 A083516 A203907 Adjacent sequences:  A227853 A227854 A227855 * A227857 A227858 A227859 KEYWORD nonn AUTHOR Pierre CAMI, Nov 01 2013 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 December 5 10:11 EST 2021. Contains 349543 sequences. (Running on oeis4.)