A140755 - OEIS

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A140755

Square array read by rows: T(n,k) = 41*n^2 + k^2 + n*k, with 20 columns.

43, 47, 53, 61, 71, 83, 97, 113, 131, 151, 173, 197, 223, 251, 281, 313, 347, 383, 421, 461, 167, 172, 179, 188, 199, 212, 227, 244, 263, 284, 307, 332, 359, 388, 419, 452, 487, 524, 563, 604, 373, 379, 387, 397, 409, 423, 439

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

The original definition of this sequence was obscure: "A prime array is embedded in a binary quadratic equation that is a transform of x^2 - x + 41".

LINKS

G. C. Greubel, Table of n, a(n) for n = 1..400

MATHEMATICA

With[{m=20}, Table[41*n^2 +k^2 +n*k, {n, m}, {k, m}]//Flatten (* G. C. Greubel, Oct 21 2023 *)

PROG

(Magma) m:=20; [41*n^2 +k^2 +n*k: k in [1..m], n in [1..m]]; // G. C. Greubel, Oct 21 2023

(SageMath) flatten([[41*n^2+k^2+n*k for k in range(1, 21)] for n in range(1, 21)]) # G. C. Greubel, Oct 21 2023

CROSSREFS

Cf. A140340, A140754 (very similar arrays).

Sequence in context: A095503 A095495 A095487 * A095479 A156783 A273595

Adjacent sequences: A140752 A140753 A140754 * A140756 A140757 A140758

KEYWORD

nonn,tabf,easy,less

AUTHOR

Aldrich Stevens (aldrichstevens(AT)msn.com), May 27 2008

EXTENSIONS

Partially edited with better definition by Omar E. Pol, Jan 11 2009

More terms from Omar E. Pol, Jan 11 2009

STATUS

approved