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A146886
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A vector matrix Markov based on the p-adic version of the modular group gamma matrix.
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0
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1, 1, 2, 4, 6, 10, 12, 16, 18, 22, 28, 30, 36, 40, 42, 46, 52, 58, 60, 66, 70, 72, 78, 82, 88, 96, 100, 102, 106, 108, 112, 126, 130, 136, 138, 148, 150, 156, 162, 166, 172, 178, 180, 190, 192, 196, 198, 210, 222, 226, 228
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| Does a(n)=A039915(n) hold for n>=2 ? [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 05 2008]
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LINKS
| Eric Weisstein's World of Mathematics, Modular Group Gamma
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FORMULA
| S = [0, -1; 1, 0], T = [1, 1; 0, 1], m(0) = T*S, m(n)=T^prime(n)*S*m(0), v(0) = [1, 0], v(n) = m(n)*v(0), a(n)=v(n)[1].
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MATHEMATICA
| Clear[S, T, M, v, n] S = {{0, -1}, {1, 0}}; T = {{1, 1}, {0, 1}}; M[0] = T.S; M[n_] := M[n] = (MatrixPower[T, Prime[n]].S).M[0]; v[0] = {1, 0}; v[n_] := v[n] = M[n].v[0]; a = Table[v[n][[1]], {n, 0, 50}]
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PROG
| (PARI) a(n)=if(n, prime(n)-1, 1)
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CROSSREFS
| a(n) = A006093(n) for n > 0.
Sequence in context: A085477 A128984 A075728 * A006093 A127965 A117891
Adjacent sequences: A146883 A146884 A146885 * A146887 A146888 A146889
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KEYWORD
| nonn,easy
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AUTHOR
| Roger L. Bagula (rlbagulatftn(AT)yahoo.com), Nov 02 2008
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EXTENSIONS
| Program, cross-ref, and editing from Charles R Greathouse IV (charles.greathouse(AT)case.edu), Apr 20 2010
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