This site is supported by donations to The OEIS Foundation.

User:Andrey Zabolotskiy

From OeisWiki
Jump to: navigation, search

Theoretical physicist, MSc in applied physics and mathematics (MIPT, 2014)

If I commented on your sequence draft, you replied, my answer is expected, but I don't answer for three days, please do not hesitate to wiki-mail me.

OEIS contributions, including:

  • miscellaneous new sequences:
  • new sequences partly taken from published sources:
    • A293060-A293063, the crystallographic point groups, subperiodic groups, and space groups, non-magnetic and magnetic, with and without enantiomorphs. My little magnum opus;
    • A292515, related to Conway's notation for knots, together with contributions to A007022, A072552, A078666, and A078672;
    • A293237 and A293238, escape probabilities for a random walk on fcc, bcc, hcp, and diamond lattices;
    • A279903, Hausdorff dimension of E{1,2};
    • A282137, a linear recurrence related to the Khmelnik representation of integers, A066321;
    • A279402-A279409, independence and domination numbers for toroidal chess graphs; also, corrections to A274947 and hence A250000, squares attacked by queens;
    • A288535-A288537, generalization of Conway's RATS to other bases;
    • A274137, МЩ;
    • A273975, a 3D array: expansion of ((xk−1)/(x−1))n;
  • contributions to miscellaneous nice sequences invented by other people (this list not only shows my contributions, which are often minor, but also shows what sequences I consider really nice or useful):
    • programs for Conway's enumeration of rational knots A122495 and links A173637;
    • nested log formula for A278813, A278452, and related sequences;
    • a program for A277795, Equisetum-like graphs;
    • corrections and program for A267794, relative of van Eck's sequence;
    • some terms and an asymptotic formula for A277828, number of coin tosses to get a run of consecutive identical result with probability >1/2;
    • realizing that A132101 is a 1D analog of A250001;
    • contributions to A282390, the tripling polyominoes;
    • contribution to A089618, "a Khinchin sequence";
    • a term for A283075, times measurable by burning ropes;
    • program for A093914, the curling number of the Thue-Morse sequence;
    • program for A287150, the fairest turn sequence for 3 players, which is in some sense a generalization of the Thue-Morse sequence;
    • contribution to A228369, the compositions of integers;
    • contribution to A001998 (I found this sequence when counted by how many ways can we stack n layers of graphene commensurately);
    • contributions to Zorach additive triangle A035312 and related sequences, including A136561;
  • cellular automata:
    • A275302-A275305, related to Langton's ant on triangular lattice, by my pupil Oleg Nikulin;
    • A275667, cellular automaton on triangular tiling, by my pupil Alexey Kovba;
    • contributions to A274369 and other Langton's ant related sequences;
  • physics:
    • I went through all sequences related to classification of n-dimensional space groups and contributed to some of them. This started from A006227(5), number of 5-dimensional space groups, and culminated in A293060-A293063 (see above);
    • removing heresy from A003673 and A005600, the fine-structure constant;
    • another formula for A260832, "numbers 2(n)", which actually arose in my research;
    • I went through all decimal expansions of constants of nature I could find and fixed the offsets in several of them;
    • references and sometimes formulas for some old physics-related sequences;
  • editorial work:
    • routine;
    • killing (with keyword dead) many old incorrect sequences;
    • editing of A054434, the Rubick's cube related sequence with unknown definition (I am particularly proud of solving this mystery);
    • a program and discussion of binary Barker codes A276690;
    • crossrefs between different versions of A035607 (it turned out that there are 5 versions of the same array, mostly not cross-referenced);
    • discussion about the balance between chemical and mathematical definitions of A134818;
    • clarifications to A040004 and A287286, related to Waring's problem mod n (it took time to verify that the difference in one term only is not a mistake);
    • help with A290772 (some cyclic Gray codes) and A292046 (related to Elias omega coding);
    • fixing old obsc sequences: compare A162997 before and after;
  • etc.

The primary mechanism of decision-making in the OEIS community is NJAS ex machina.

Beware of the imp!