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 A085766 Smallest m such that n divides the tetrahedral number A000292(m+1). 0
 1, 1, 6, 1, 2, 6, 4, 5, 24, 2, 8, 6, 10, 5, 7, 13, 14, 25, 16, 3, 6, 9, 20, 7, 22, 10, 78, 5, 26, 7, 28, 29, 8, 14, 4, 25, 34, 17, 24, 7, 38, 6, 40, 9, 24, 21, 44, 15, 46, 22, 15, 11, 50, 78, 8, 5, 16, 26, 56, 7, 58, 29, 25, 61, 12, 42, 64, 14, 43, 13, 68, 53, 70, 34, 24, 17, 19, 25, 76, 13 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS EXAMPLE Let te(m)=(m+1)(m+2)(m+3)/6. Then te(1)=4, te(2)=10, te(3)=20, te(4)=35, te(5)=56 and te(6)=84. te(6) is the first tetrahedral number divisible by 3, hence a(3)=6. PROG (PARI) te(n)=(n+1)*(n+2)*(n+3)/6 for (n=1, 50, c=1; while (te(c)%n!=0, c++); print1(c", ")) (PARI) first(n) = {my(res = vector(n), todo = n); res[1] = 1; todo--; for(i = 1, oo, t = binomial(i + 2, 3); d = divisors(t); for(j = 1, #d, if(d[j] <= n && res[d[j]] == 0, res[d[j]] = i - 1; todo--; if(todo <= 0, return(res); ) ) ) ) } \\ David A. Corneth, Mar 22 2021 CROSSREFS Cf. A011772 (triangular numbers), A019554 (squares). Sequence in context: A070682 A216415 A112828 * A002329 A053453 A347197 Adjacent sequences: A085763 A085764 A085765 * A085767 A085768 A085769 KEYWORD nonn AUTHOR Jon Perry, Jul 22 2003 EXTENSIONS More terms from David Wasserman, Feb 10 2005 Definition corrected by David A. Corneth, Mar 22 2021 STATUS approved

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Last modified January 27 21:49 EST 2023. Contains 359849 sequences. (Running on oeis4.)