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A114023 Squares of the form semiprime(k) + k-th triangular number. 0
4, 16, 100, 144, 33489, 82369, 41088506209, 95056905969, 196978855329, 4901432910724, 6047212155664, 26601838343809, 247869502464123136 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(14) > 10^18. - Donovan Johnson, Jun 04 2013

LINKS

Table of n, a(n) for n=1..13.

PROG

(PARI) lista(nn) = {n = -1; for (i=1, nn, if (bigomega(i) == 2, n++; if (issquare(sq=i + n*(n+1)/2), print1(sq, ", ")); ); ); } \\ Michel Marcus, Jun 03 2013

CROSSREFS

Cf. A000217, A001358, A111440, A112662.

Sequence in context: A209299 A091040 A029985 * A145823 A121142 A318693

Adjacent sequences:  A114020 A114021 A114022 * A114024 A114025 A114026

KEYWORD

nonn

AUTHOR

Giovanni Teofilatto, Feb 01 2006

EXTENSIONS

More terms from Michel Marcus, Jun 03 2013

a(7)-a(13) from Donovan Johnson, Jun 04 2013

STATUS

approved

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Last modified May 27 16:48 EDT 2022. Contains 354110 sequences. (Running on oeis4.)