A105340 a(n) = n*(n+1)/2 mod 2048.

0, 1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78, 91, 105, 120, 136, 153, 171, 190, 210, 231, 253, 276, 300, 325, 351, 378, 406, 435, 465, 496, 528, 561, 595, 630, 666, 703, 741, 780, 820, 861, 903, 946, 990, 1035, 1081, 1128, 1176, 1225, 1275, 1326, 1378, 1431, 1485, 1540, 1596, 1653, 1711, 1770, 1830, 1891, 1953, 2016, 32

Offset: 0

Author

Oscar Takeshita, May 01 2005

Keywords

• nonn
• easy

Comments

Period 4096. - Charles R Greathouse IV, Oct 16 2012

Links

• Index entries for linear recurrences with constant coefficients, order 4095.

Crossrefs

See A105198 for further information.

Cf. A000217.

Programs

Mathematica

Mod[Accumulate[Range[0,70]],2048] (* Harvey P. Dale, Sep 18 2019 *)

PARI

a(n)=n*(n+1)/2%2048 \\ Charles R Greathouse IV, Oct 16 2012

Python

def A105340(n): return (n*(n+1)>>1)&2047 # Chai Wah Wu, Apr 17 2025

Extensions

Removed formulas that were wrong at indices >= 65 because the "mod 2048" part of the definition had been ignored R. J. Mathar, Jan 26 2010