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A324899 Odd numbers n for which sigma(n) == 3 (mod 4). 3
25, 169, 225, 289, 841, 1225, 1369, 1521, 1681, 2025, 2601, 2809, 3025, 3721, 5329, 7569, 7921, 8281, 9025, 9409, 10201, 11025, 11881, 12321, 12769, 13225, 13689, 14161, 15129, 15625, 18225, 18769, 20449, 22201, 23409, 24025, 24649, 25281, 27225, 29929, 32761, 33489, 34969, 37249, 38809, 41209, 46225, 47961, 52441, 54289, 55225 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

These are all squares. Square roots are in A324909.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for sequences related to sigma(n)

PROG

(PARI) isA324899(n) = ((n%2)&&3==(sigma(n)%4));

CROSSREFS

Intersection of A016754 and A072462.

Cf. A000203, A324909 (square roots).

Cf. A325311 (a subsequence).

Sequence in context: A125335 A126493 A255419 * A198436 A080109 A017126

Adjacent sequences:  A324896 A324897 A324898 * A324900 A324901 A324902

KEYWORD

nonn

AUTHOR

Antti Karttunen, Apr 20 2019

STATUS

approved

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Last modified October 23 08:57 EDT 2019. Contains 328345 sequences. (Running on oeis4.)