cp's OEIS Frontend

A173825 List of numbers k such that k=6*r+1=m*q, m>=q and n>=g where number m is 6*n+1 or 6*n-1 and number q is 6*g+1 or 6*g-1.

%I A173825 #7 May 04 2024 09:23:48
%S A173825 1,7,25,49,13,55,91,121,169,19,85,133,187,247,289,361,25,115,175,253,
%T A173825 325,391,475,529,625,31,145,217,319,403,493,589,667,775,841,961,37,
%U A173825 175,259,385,481,595,703,805,925,1015,1147,1225,1369,43,205,301,451,559,697
%N A173825 List of numbers k such that k=6*r+1=m*q, m>=q and n>=g where number m is 6*n+1 or 6*n-1 and number q is 6*g+1 or 6*g-1.
%C A173825 Triangle begins:
%C A173825   1 (for row n=0)
%C A173825   7 25 49 (for row n=1)
%C A173825   13 55 91 121 169 (for row n=2)
%C A173825   19 85 133 187 247 289 361 (for row n=3)
%C A173825   25 115 175 253 325 391 475 529 625 (for row n=4)
%C A173825   31 145 217 319 403 493 589 667 775 841 961 (for row n=5)
%e A173825 a(1)=1 because 1=6*0+1=1*1=(6*0+1)*(6*0+1);
%e A173825 a(2)=7 because 7=6*1+1=7*1=(6*1+1)*(6*0+1);
%e A173825 a(3)=25 because 25=6*4+1=5*5=(6*1-1)*(6*1-1);
%e A173825 a(4)=49 because 49=6*8+1=7*7=(6*1+1)*(6*1+1);
%e A173825 a(5)=13 because 13=13*1=(6*2+1)*(6*0+1);
%e A173825 a(6)=55 because 55=6*9+1=11*5=(6*2-1)*(6*1-1);
%e A173825 a(7)=91 because 91=13*7=(6*2+1)*(6*1+1);
%e A173825 a(8)=121 because 121=6*20+1=11*11=(6*2-1)*(6*2-1);
%e A173825 a(9)=169 because 169=6*28+1=13+13=(6*2+1)*(6*2+1);
%e A173825 a(10)=19 because 19=6*3+1=19*1=(6*3+1)*(6*0+1).
%Y A173825 Cf. A007310.
%K A173825 nonn
%O A173825 1,2
%A A173825 _Juri-Stepan Gerasimov_, Feb 26 2010
%E A173825 Entries checked by _R. J. Mathar_, Apr 14 2010