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A240527 Indices of 7-almost prime triangular numbers. 2
64, 95, 127, 135, 143, 144, 159, 160, 175, 191, 192, 207, 215, 216, 242, 243, 272, 279, 296, 323, 335, 350, 360, 368, 375, 404, 405, 415, 416, 431, 432, 448, 455, 459, 464, 479, 485, 504, 527, 528, 543, 544, 559, 584, 594, 615, 620, 623, 647, 656, 672, 719 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

FORMULA

{ m :  A069904(m) = 7 }. - Alois P. Heinz, Aug 05 2019

EXAMPLE

a(1) = 64 because A000217(64) = 64*(64+1)/2 = 2080 = 2^5 * 5 * 13 is a 7-almost prime.

MATHEMATICA

Flatten[Position[Accumulate[Range[800]], _?(PrimeOmega[#]==7&)]]

CROSSREFS

Cf. A000217, A069904, A108815, A114435, A114436, A114437, A164977.

Sequence in context: A119894 A138667 A290462 * A262743 A176819 A114407

Adjacent sequences:  A240524 A240525 A240526 * A240528 A240529 A240530

KEYWORD

nonn

AUTHOR

Vincenzo Librandi, Apr 07 2014

STATUS

approved

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Last modified December 9 08:41 EST 2021. Contains 349627 sequences. (Running on oeis4.)