Search: id:A161664 Results 1-1 of 1 results found. %I A161664 %S A161664 0,0,1,2,5,7,12,16,22,28,37,43,54,64,75,86,101,113,130,144,161,179,200, %T A161664 216,238,260,283,305,332,354,383,409,438,468,499,526,561,595,630,662, %U A161664 701,735,776,814,853,895,940,978,1024,1068,1115,1161,1212,1258,1309 %N A161664 Partial sums of A049820. %C A161664 The original definition was: Safe periods for the emergence of cicada species on prime number cycles. %C A161664 See Table 9 in reference, page 75, which together with the chart on page 73 (see link) provide a mathematical basis for the emergence of cicada species on prime number cycles. %D A161664 E. Haga, Eratosthenes goes bugs! Exploring Prime Numbers, 2007, pp 71-80; first publication 1994. %H A161664 E. Haga, Prime Safe Periods %H A161664 A. Baker, Are there Genuine Mathematical Explanations of Physical Phenomena?, Mind 114 (454) (2005) 223-238. %H A161664 G. F. Webb, The prime number periodical Cicada problem, Discr. Cont. Dyn. Syst. 1 (3) (2001) 387 %F A161664 a(n) = A000217(n)-A006218(n). %e A161664 a(8) in A000217 minus a(8) in A006218 = a(7) above (28-16=12). %e A161664 Referring to the chart referenced, when nth year = 7 there are 16 x-markers. %e A161664 These represent unsafe periods for cicada emergence: 28-16=12 safe periods. %e A161664 The percent of safe periods for the entire 7 years is 12/28=~42.86%; for year 7 alone the calculation is 5/7 = 71.43%, a relatively good time to emerge. %Y A161664 A000217, A049820, A006218. %Y A161664 Sequence in context: A080182 A001318 A024702 this_sequence A080547 A080555 A024924 %Y A161664 Adjacent sequences: A161661 A161662 A161663 this_sequence A161665 A161666 A161667 %K A161664 easy,nonn %O A161664 1,4 %A A161664 Enoch Haga (Enokh(AT)comcast.net), Jun 15 2009 %E A161664 Simplified definition, offset corrected and partially edited by Omar E. Pol (info(AT)polprimos.com), Jun 18 2009 Search completed in 0.001 seconds