cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A077128 Smallest number greater than the previous term which is relatively prime to each of the group of the next n numbers.

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%I A077128 #10 Aug 07 2015 02:44:00
%S A077128 2,5,7,11,17,23,29,37,47,59,67,79,97,107,127,137,157,173,191,211,233,
%T A077128 257,277,307,331,353,379,409,439,467,499,541,563,599,631,673,709,743,
%U A077128 787,821,863,907,947,991,1039,1087,1129,1181,1229,1277,1327,1381,1433
%N A077128 Smallest number greater than the previous term which is relatively prime to each of the group of the next n numbers.
%C A077128 Conjecture : every member is a prime.
%e A077128 a(6) = 23 is the smallest number coprime to 16,17,18,19,20 and 21. - _R. J. Mathar_, Sep 02 2008
%p A077128 A000217 := proc(n) n*(n+1)/2 ; end: A077128 := proc(n) option remember ; local ts,a,goodk,k ; if n = 1 then RETURN(2) ; fi; ts := [seq(A000217(n-1)+i,i=1..n)] ; for a from procname(n-1)+1 do goodk := true ; for k in ts do if gcd(a,k) <> 1 then goodk := false; break ; fi; od: if goodk then RETURN(a) ; fi; od: end: for n from 1 to 100 do printf("%d,",A077128(n)) ; od: # _R. J. Mathar_, Sep 02 2008
%Y A077128 Cf. A097050. - _R. J. Mathar_, Sep 02 2008
%K A077128 nonn
%O A077128 1,1
%A A077128 _Amarnath Murthy_, Oct 29 2002
%E A077128 Extended beyond a(10) by _R. J. Mathar_, Sep 02 2008