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 A002704 Sets with a congruence property. (Formerly M2146 N0855) 6
 2, 26, 938, 42800, 2130458, 111557594, 6041272682, 335089258634, 18922687509962, 1083572842675610, 62744027461625648, 3666433604712457466, 215879610645469496234, 12792865816027823374874, 762278349313657804740842, 45638342462133835019322554 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 REFERENCES N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Rosa, Alexander; Znam, Stefan, A combinatorial problem in the theory of congruences (Russian with English summary), Mat.-Fys. Casopis Sloven. Akad. Vied 15 1965 49-59. [Annotated scanned copy.] Rosa, Alexander; Znam, Stefan, A remark on a combinatorial problem (Russian with English summary), Mat.-Fyz. Casopis Sloven. Akad. Vied 15 1965 313-316. [Annotated scanned copy] See Table 3. FORMULA See Maple code! MAPLE p := proc(r, s, k)     option remember;     if r = 0 then         1;     elif r < 0 then         0;     elif s < 0 then         0;     elif igcd(s, 2*k+1) > 1 then         procname(r, s-1, k) ;     else         procname(r, s-1, k)+procname(r-s, s-1, k) ;     end if; end proc: Q := proc(n, k)     local q, knrat, alpha, m ;     q := 0 ;     knrat := (2*k*n^2+n^2+k^2)/4/k ;     if type(knrat, 'integer') then         for alpha from 0 to knrat do             m := 2*n+n/k ;             if modp(2*alpha, m) = modp(knrat, m) then                 q := q+p(alpha, n+(n-k)/2/k, k) ;             end if;         end do:     end if;     q ; end proc: A002704 := proc(n)     nloc := 3+6*n ;     Q(nloc, 3) ; end proc: seq(A002704(n), n=0..15) ; # R. J. Mathar, Oct 21 2015 CROSSREFS Cf. A002703, A002705, A262570, A262583, A262584. Sequence in context: A059516 A210672 A173103 * A015215 A158120 A209916 Adjacent sequences:  A002701 A002702 A002703 * A002705 A002706 A002707 KEYWORD nonn AUTHOR EXTENSIONS More terms from R. J. Mathar, Oct 21 2015 STATUS approved

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