A389700 Numbers m with deficiency 30: sigma(m) - 2*m = -30.

31, 51, 135, 148, 976, 10048, 34335, 138496, 449295, 33673216, 537346048, 8591835136, 4439852974095, 35184493723648, 1956860570050575, 9007201200898048, 221753180448460815, 747406020889133775, 36893488271973154816, 9444732967732155252736

Offset

1,1

Comments

For k in A156982, 2^(k-1)*(2^k+29) is a term. Bigger term of this form is 38685626227795676939419648 (k=43). [Updated by Max Alekseyev, Nov 05 2025]

Links

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

Prog

(PARI) isok(m) = sigma(m) - 2*m == -30; \\ Michel Marcus, Oct 17 2025

Crossrefs

Deficiency k: A191363 (k=2), A125246 (k=4), A141548 (k=6), A125247 (k=8), A101223 (k=10), A141549 (k=12), A141550 (k=14), A125248 (k=16), A223608 (k=18), A223607 (k=20), A223606 (k=22), A385255 (k=24), A275702 (k=26), A387352 (k=32), A175730 (k=42), A101259 (k=54), A275997 (k=64).

Abundance k: A088831 (k=2), A088832 (k=4), A087167 (k=6), A088833 (k=8), A223609 (k=10), A141545 (k=12), A141546 (k=14), A141547 (k=16), A223610 (k=18), A223611 (k=20), A223612 (k=22), A223613 (k=24), A275701 (k=26), A175989 (k=32), A275996 (k=64), A292626 (k=128).

Cf. A000203, A033880, A156982.

Sequence in context: A068779 A068473 A275628 * A176507 A163321 A182380

Adjacent sequences: A389697 A389698 A389699 * A389701 A389702 A389703

Keyword

nonn

Author

Alexander Violette, Oct 11 2025

Extensions

a(13)-a(20) confirmed and added by Max Alekseyev, Nov 05 2025

Status

approved