A107973 Numbers of the form a^2 + b for a= 21 to 40 and b= 20 to 1 step -1.

461, 503, 547, 593, 641, 691, 743, 797, 853, 911, 971, 1033, 1097, 1163, 1231, 1301, 1373, 1447, 1523, 1601

Offset

1,1

Comments

Complete list of 20 prime numbers also of the form n^2+n+41 for n=20 to 39

Links

Table of n, a(n) for n=1..20.

Example

21*21+20=461
22*22+19=503
23*23+18=547

Mathematica

#[[1]]^2+#[[2]]&/@Thread[{Range[21, 40], Range[20, 1, -1]}] (* Harvey P. Dale, Jan 01 2018 *)

Crossrefs

Sequence in context: A377747 A264242 A358894 * A227994 A142832 A277989

Adjacent sequences: A107970 A107971 A107972 * A107974 A107975 A107976

Keyword

fini,full,nonn

Author

Pierre CAMI, Jun 12 2005

Status

approved