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 A275018 a(n) = A278846(n)/8. 1
 0, 0, 0, 0, 0, 1, 1, 5, 6, 10, 11, 19, 20, 29, 33, 38, 43, 56, 60, 76, 81, 90, 98, 118, 121, 138, 147, 163, 172, 197, 202, 230, 243, 260, 273, 294, 303, 336, 352, 373, 384, 421, 430, 470, 487, 508, 528, 572, 583, 623, 640 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,8 LINKS Indranil Ghosh and Chai Wah Wu, Table of n, a(n) for n = 0..10000 (terms n = 0..200 from Indranil Ghosh) PROG (Python) def t(n):     s=0     for a in range(0, n+1):         for b in range(0, n+1):             for c in range(0, n+1):                 for d in range(0, n+1):                     if (a!=b  and a!=d and b!=d and c!=a and c!=b and c!=d):                         if abs(a*d-b*c)==1:                             s+=1     return s for i in range(0, 201):     print str(i)+" "+str(t(i)/8) \\ Indranil Ghosh, Nov 30, 2016. CROSSREFS Cf. A278846. Sequence in context: A064957 A008851 A079259 * A029772 A046827 A064827 Adjacent sequences:  A275015 A275016 A275017 * A275019 A275020 A275021 KEYWORD nonn AUTHOR Indranil Ghosh, Nov 30 2016 STATUS approved

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Last modified July 24 06:56 EDT 2021. Contains 346273 sequences. (Running on oeis4.)