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%I #12 Mar 04 2014 05:11:07
%S 1,1,3,5,7,9,11,11,13,15,17,19,21,23,25,27,29,31,31,33,35,37,39,41,43,
%T 45,47,49,51,53,55,57,59,61,61,63,65,67,69,71,73,75,77,79,81,83,85,87,
%U 89,91,93,95,97,99,101,101,103,105,107,109,111,113,115,117,119,121,123,125,127,129,131,133,135,137,139,141,143,145,147,149,151,151,153,155,157,159,161,163,165,167,169,171,173,175,177,179,181,183,185,187
%N A P_7-stuttered arithmetic progression with a(n+1)=a(n) if n is not a heptagonal number, a(n+1)=a(n)+2 otherwise.
%C P_7(i) = the i-th heptagonal number.
%H Douglas E. Iannucci and Donna Mills-Taylor. <a href="http://www.cs.uwaterloo.ca/journals/JIS/IANN/iann1.html">On Generalizing the Connell Sequence</a>. Journal of Integer Sequences 2 (1999), Article 99.1.7.
%H Grady D. Bullington, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL10/Bullington/bullington7.html">The Connell Sum Sequence</a>, J. Integer Seq. 10 (2007), Article 07.2.6. (includes direct formula for a(n))
%F a(n) = A045930(n)-n+1.
%o (PARI) isHeptag(n) = {if (! issquare(40*n+9, &res), return (0)); if ((res + 3) % 10, return (0), return (1));}
%o lista(m) = {aa = 1; for (i=1, m, print1(aa, ", "); if (! isHeptag(i), aa += 2););} \\ _Michel Marcus_, Apr 01 2013
%Y Cf. A001614, A122793, A122794, A122795, A122796, A122797, A122798, A122800.
%K nonn,easy
%O 1,3
%A Grady Bullington (bullingt(AT)uwosh.edu), Sep 14 2006
%E Definition corrected by _Michel Marcus_, Apr 01 2013
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