Search: id:A005574 Results 1-1 of 1 results found. %I A005574 M1010 %S A005574 1,2,4,6,10,14,16,20,24,26,36,40,54,56,66,74,84,90,94,110,116,120, %T A005574 124,126,130,134,146,150,156,160,170,176,180,184,204,206,210,224, %U A005574 230,236,240,250,256,260,264,270,280,284,300,306,314,326,340,350 %N A005574 Numbers n such that n^2 + 1 is prime. %C A005574 Hardy and Littlewood conjectured that the asymptotic number of elements in this sequence not exceeding n is approximately c*sqrt(n)/ln(n) for some constant c. - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Apr 06 2006 %D A005574 R. K. Guy, "Unsolved Problems in Number Theory", 3rd edition, A2 %D A005574 G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers, 5th ed., Oxford Univ. Press, 1979, th. 17. %D A005574 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %H A005574 T. D. Noe, Table of n, a(n) for n=1..10000 %H A005574 F. Ellermann, Primes of the form (m^2)+1 up to 10^6 %H A005574 Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics. %H A005574 Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics. %H A005574 Eric Weisstein's World of Mathematics, Near-Square Prime %H A005574 Marek Wolf, Search for primes of the form m^2+1 %t A005574 Select[Range[350], PrimeQ[ #^2 + 1] &] - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Apr 06 2006 %Y A005574 a(n) = A090693(n)-1. %Y A005574 Cf. A002522, A001912, A002496, A062325, A090693. %Y A005574 Cf. A000068, A006314, A006313, A006315, A006316, A056994, A056995 %Y A005574 Sequence in context: A104692 A066755 A089238 this_sequence A109807 A125964 A139544 %Y A005574 Adjacent sequences: A005571 A005572 A005573 this_sequence A005575 A005576 A005577 %K A005574 nonn,easy,nice %O A005574 1,2 %A A005574 N. J. A. Sloane (njas(AT)research.att.com). Search completed in 0.002 seconds