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A060731 a(n) = a(n-1) + a(n - 1 minus the number of terms of a(k) == (mod 4) so far). 0
1, 2, 3, 4, 7, 11, 14, 25, 36, 50, 64, 89, 125, 175, 225, 314, 378, 467, 592, 817, 992, 1306, 1684, 2062, 2529, 2996, 3988, 4580, 5572, 6878, 9407, 10399, 12928, 15457, 19445, 21507, 25495, 31067, 35647, 40227, 49634, 60033, 66911, 77310, 92767 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..45.

EXAMPLE

a(5) = a(4) + a(4 - the number of terms congruent to 1 (mod 4) so far) = a(4) + a(4-1) = 4 + 3 = 7.

MATHEMATICA

m[ 1 ] = 1; m[ 2 ] = 2; m[ 3 ] = 3; a[ 4 ] = 4; m[ n_Integer ] := m[ n ] = Block[ {a = b = c = d = 0}, Do[ Switch[ Mod[ m[ k ], 4 ], 0, a++, 1, b++, 2, c++, 3, d++ ], {k, 1, n - 1} ]; Switch[ Mod[ n, 4 ], 0, m[ n - 1 ] + m[ n - 1 - a ], 1, m[ n - 1 ] + m[ n - 1 - b ], 2, m[ n - 1 ] + m[ n - 1 - c ], 3, m[ n - 1 ] + m[ n - 1 - d ] ] ]; Table[ m[ n ], {n, 1, 50} ]

CROSSREFS

Sequence in context: A279071 A171027 A064933 * A238492 A140827 A125621

Adjacent sequences:  A060728 A060729 A060730 * A060732 A060733 A060734

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Apr 22 2001

STATUS

approved

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Last modified December 6 14:15 EST 2019. Contains 329806 sequences. (Running on oeis4.)